diff --git a/application/applicationextension.inc.php b/application/applicationextension.inc.php
index d1aa296e44..b40bf1e945 100644
--- a/application/applicationextension.inc.php
+++ b/application/applicationextension.inc.php
@@ -1929,41 +1929,76 @@ public static function GetClass($oData, $sParamName)
 	 * @return array of class => list of attributes (see RestResultWithObjects::AddObject that uses it)
 	 * @throws Exception
 	 */
-	public static function GetFieldList($sClass, $oData, $sParamName)
+	public static function GetFieldList($sClass, $oData, $sParamName, $bFailIfNotFound = true)
 	{
 		$sFields = self::GetOptionalParam($oData, $sParamName, '*');
-		$aShowFields = array();
-		if ($sFields == '*')
-		{
-			foreach (MetaModel::ListAttributeDefs($sClass) as $sAttCode => $oAttDef)
-			{
-				$aShowFields[$sClass][] = $sAttCode;
-			}
+		return match($sFields) {
+			'*' => self::GetFieldListForClass($sClass),
+			'*+' => self::GetFieldListForParentClass($sClass),
+			default => self::GetLimitedFieldListForClass($sClass, $sFields, $sParamName, $bFailIfNotFound),
+		};
+	}
+
+	public static function HasRequestedExtendedOutput(string $sFields): bool
+	{
+		return match($sFields) {
+			'*' => false,
+			'*+' => true,
+			default => substr_count($sFields, ':') > 1,
+		};
+	}
+
+	public static function HasRequestedAllOutputFields(string $sFields): bool
+	{
+		return match($sFields) {
+			'*', '*+' => true,
+			default => false,
+		};
+	}
+
+	protected static function GetFieldListForClass(string $sClass): array
+	{
+		return [$sClass => array_keys(MetaModel::ListAttributeDefs($sClass))];
+	}
+
+	protected static function GetFieldListForParentClass(string $sClass): array
+	{
+		$aFieldList = array();
+		foreach (MetaModel::EnumChildClasses($sClass, ENUM_CHILD_CLASSES_ALL) as $sRefClass) {
+			$aFieldList = array_merge($aFieldList, self::GetFieldListForClass($sRefClass));
 		}
-		elseif ($sFields == '*+')
-		{
-			foreach (MetaModel::EnumChildClasses($sClass, ENUM_CHILD_CLASSES_ALL) as $sRefClass)
-			{
-				foreach (MetaModel::ListAttributeDefs($sRefClass) as $sAttCode => $oAttDef)
-				{
-					$aShowFields[$sRefClass][] = $sAttCode;
+		return $aFieldList;
+	}
+
+	protected static function GetLimitedFieldListForSingleClass(string $sClass, string $sFields, string $sParamName, bool $bFailIfNotFound = true): array
+	{
+		$aFieldList = [$sClass => []];
+		foreach (explode(',', $sFields) as $sAttCode) {
+			$sAttCode = trim($sAttCode);
+			if (($sAttCode == 'id') || (MetaModel::IsValidAttCode($sClass, $sAttCode))) {
+				$aFieldList[$sClass][] = $sAttCode;
+			} else {
+				if ($bFailIfNotFound) {
+					throw new Exception("$sParamName: invalid attribute code '$sAttCode' for class '$sClass'");
 				}
 			}
 		}
-		else
-		{
-			foreach (explode(',', $sFields) as $sAttCode)
-			{
-				$sAttCode = trim($sAttCode);
-				if (($sAttCode != 'id') && (!MetaModel::IsValidAttCode($sClass, $sAttCode)))
-				{
-					throw new Exception("$sParamName: invalid attribute code '$sAttCode'");
-				}
-				$aShowFields[$sClass][] = $sAttCode;
-			}
+		return $aFieldList;
+	}
+
+	protected static function GetLimitedFieldListForClass(string $sClass, string $sFields, string $sParamName, bool $bFailIfNotFound = true): array
+	{
+		if (!str_contains($sFields, ':')) {
+			return self::GetLimitedFieldListForSingleClass($sClass, $sFields, $sParamName, $bFailIfNotFound);
 		}
 
-		return $aShowFields;
+		$aFieldList = [];
+		$aFieldListParts = explode(';', $sFields);
+		foreach ($aFieldListParts as $sClassFields) {
+			list($sSubClass, $sSubClassFields) = explode(':', $sClassFields);
+			$aFieldList = array_merge($aFieldList, self::GetLimitedFieldListForSingleClass(trim($sSubClass), trim($sSubClassFields), $sParamName, $bFailIfNotFound));
+		}
+		return $aFieldList;
 	}
 
 	/**
diff --git a/core/restservices.class.inc.php b/core/restservices.class.inc.php
index b66ed5e090..ba93092744 100644
--- a/core/restservices.class.inc.php
+++ b/core/restservices.class.inc.php
@@ -185,23 +185,7 @@ class RestResultWithObjects extends RestResult
 	/** @var array "DBObject_class:DBObject_key" as key, {@see \ObjectResult} as value */
 	public $objects;
 
-	/**
-	 * Report the given object
-	 *
-	 * @api
-	 * @param int $iCode An error code (RestResult::OK is no issue has been found)
-	 * @param string $sMessage Description of the error if any, an empty string otherwise
-	 * @param DBObject $oObject The object being reported
-	 * @param array|null $aFieldSpec An array of class => attribute codes (Cf. RestUtils::GetFieldList). List of the attributes to be reported.
-	 * @param boolean $bExtendedOutput Output all of the link set attributes ?
-	 *
-	 * @return void
-	 * @throws \ArchivedObjectException
-	 * @throws \CoreException
-	 * @throws \CoreUnexpectedValue
-	 * @throws \MySQLException
-	 */
-	public function AddObject($iCode, $sMessage, $oObject, $aFieldSpec = null, $bExtendedOutput = false)
+	public function PrepareObject($iCode, $sMessage, $oObject, $aFieldSpec = null, $bExtendedOutput = false)
 	{
 		$sClass = get_class($oObject);
 		$oObjRes = new ObjectResult($sClass, $oObject->GetKey());
@@ -232,6 +216,28 @@ public function AddObject($iCode, $sMessage, $oObject, $aFieldSpec = null, $bExt
 			$oObjRes->AddField($oObject, $sAttCode, $bExtendedOutput);
 		}
 
+		return $oObjRes;
+	}
+
+	/**
+	 * Report the given object
+	 *
+	 * @api
+	 * @param int $iCode An error code (RestResult::OK is no issue has been found)
+	 * @param string $sMessage Description of the error if any, an empty string otherwise
+	 * @param DBObject $oObject The object being reported
+	 * @param array|null $aFieldSpec An array of class => attribute codes (Cf. RestUtils::GetFieldList). List of the attributes to be reported.
+	 * @param boolean $bExtendedOutput Output all of the link set attributes ?
+	 *
+	 * @return void
+	 * @throws \ArchivedObjectException
+	 * @throws \CoreException
+	 * @throws \CoreUnexpectedValue
+	 * @throws \MySQLException
+	 */
+	public function AddObject($iCode, $sMessage, $oObject, $aFieldSpec = null, $bExtendedOutput = false)
+	{
+		$oObjRes = $this->PrepareObject($iCode, $sMessage, $oObject, $aFieldSpec, $bExtendedOutput);
 		$sObjKey = get_class($oObject).'::'.$oObject->GetKey();
 		$this->objects[$sObjKey] = $oObjRes;
 	}
@@ -247,6 +253,45 @@ public function SanitizeContent()
 	}
 }
 
+/**
+ * @package RESTAPI
+ * @api
+ */
+class RestResultWithObjectSets extends RestResultWithObjects
+{
+	private $current_object = null;
+
+	public function MakeNewObjectSet()
+	{
+		$arr = array();
+		$this->current_object = &$arr;
+		$this->objects[] = &$arr;
+	}
+
+	/**
+	 * Report the given object
+	 *
+	 * @api
+	 * @param string $sObjectAlias Name of the subobject, usually the OQL class alias
+	 * @param int $iCode An error code (RestResult::OK is no issue has been found)
+	 * @param string $sMessage Description of the error if any, an empty string otherwise
+	 * @param DBObject $oObject The object being reported
+	 * @param array|null $aFieldSpec An array of class => attribute codes (Cf. RestUtils::GetFieldList). List of the attributes to be reported.
+	 * @param boolean $bExtendedOutput Output all of the link set attributes ?
+	 *
+	 * @return void
+	 * @throws \ArchivedObjectException
+	 * @throws \CoreException
+	 * @throws \CoreUnexpectedValue
+	 * @throws \MySQLException
+	 */
+	public function AppendSubObject($sObjectAlias, $iCode, $sMessage, $oObject, $aFieldSpec = null, $bExtendedOutput = false)
+	{
+		$oObjRes = $this->PrepareObject($iCode, $sMessage, $oObject, $aFieldSpec, $bExtendedOutput);
+		$this->current_object[$sObjectAlias] = $oObjRes;
+	}
+}
+
 /**
  * @package RESTAPI
  * @api
@@ -526,14 +571,21 @@ public function ExecOperation($sVersion, $sVerb, $aParams)
 			break;
 	
 		case 'core/get':
-			$sClass = RestUtils::GetClass($aParams, 'class');
+			$sClassParam =  RestUtils::GetMandatoryParam($aParams, 'class');
 			$key = RestUtils::GetMandatoryParam($aParams, 'key');
-			$aShowFields = RestUtils::GetFieldList($sClass, $aParams, 'output_fields');
-			$bExtendedOutput = (RestUtils::GetOptionalParam($aParams, 'output_fields', '*') == '*+');
+			$sShowFields = RestUtils::GetOptionalParam($aParams, 'output_fields', '*');
 			$iLimit = (int)RestUtils::GetOptionalParam($aParams, 'limit', 0);
 			$iPage = (int)RestUtils::GetOptionalParam($aParams, 'page', 1);
 
-			$oObjectSet = RestUtils::GetObjectSetFromKey($sClass, $key, $iLimit, self::getOffsetFromLimitAndPage($iLimit, $iPage));
+			// Validate the class(es)
+			$aClass = explode(',', $sClassParam);
+			foreach ($aClass as $sClass) {
+				if (!MetaModel::IsValidClass(trim($sClass))) {
+					throw new Exception("class '$sClass' is not valid");
+				}
+			}
+
+			$oObjectSet = RestUtils::GetObjectSetFromKey($sClassParam, $key, $iLimit, self::getOffsetFromLimitAndPage($iLimit, $iPage));
 			$sTargetClass = $oObjectSet->GetFilter()->GetClass();
 	
 			if (UserRights::IsActionAllowed($sTargetClass, UR_ACTION_READ) != UR_ALLOWED_YES)
@@ -551,23 +603,68 @@ public function ExecOperation($sVersion, $sVerb, $aParams)
 			    $oResult->code = RestResult::INVALID_PAGE;
 			    $oResult->message = "The request page number is not valid. It must be an integer greater than 0";
             }
-			else
+			elseif (count($oObjectSet->GetSelectedClasses()) > 1)
 			{
-                                if (!$bExtendedOutput && RestUtils::GetOptionalParam($aParams, 'output_fields', '*') != '*')
-                                {
-                                        $aFields = $aShowFields[$sClass];
-                                        //Id is not a valid attribute to optimize
-                                        if (in_array('id', $aFields))
-                                        {
-                                            unset($aFields[array_search('id', $aFields)]);
-                                        }
-                                        $aAttToLoad = array($oObjectSet->GetClassAlias() => $aFields);
-                                        $oObjectSet->OptimizeColumnLoad($aAttToLoad);
-                                }
-
-				while ($oObject = $oObjectSet->Fetch())
-				{
-					$oResult->AddObject(0, '', $oObject, $aShowFields, $bExtendedOutput);
+				$oResult = new RestResultWithObjectSets();
+				$aCache = [];
+				$aShowFields = [];
+				foreach ($oObjectSet->GetSelectedClasses() as $sSelectedClass) {
+					$aShowFields = array_merge( $aShowFields, RestUtils::GetFieldList($sSelectedClass, $aParams, 'output_fields', false));
+				}
+
+				while ($oObjects = $oObjectSet->FetchAssoc()) {
+					$oResult->MakeNewObjectSet();
+
+					foreach ($oObjects as $sAlias => $oObject) {
+						if (!$oObject) {
+							continue;
+						}
+
+						if (!array_key_exists($sAlias, $aCache)) {
+							$sClass = get_class($oObject);
+							$bExtendedOutput = RestUtils::HasRequestedExtendedOutput($sShowFields);
+
+							if (!RestUtils::HasRequestedAllOutputFields($sShowFields)) {
+								$aFields = $aShowFields[$sClass];
+								//Id is not a valid attribute to optimize
+								if ($aFields && in_array('id', $aFields)) {
+									unset($aFields[array_search('id', $aFields)]);
+								}
+								$aAttToLoad = [$sAlias => $aFields];
+								$oObjectSet->OptimizeColumnLoad($aAttToLoad);
+							}
+							$aCache[$sAlias] = [
+								'aShowFields' => $aShowFields,
+								'bExtendedOutput' => $bExtendedOutput,
+							];
+						} else {
+							$aShowFields = $aCache[$sAlias]['aShowFields'];
+							$bExtendedOutput = $aCache[$sAlias]['bExtendedOutput'];
+						}
+
+						$oResult->AppendSubObject($sAlias, 0, '', $oObject, $aShowFields, $bExtendedOutput);
+					}
+				}
+				$oResult->message = "Found: ".$oObjectSet->Count();
+			} else {
+				$aShowFields =[];
+				foreach ($aClass  as $sSelectedClass) {
+					$sSelectedClass = trim($sSelectedClass);
+					$aShowFields = array_merge($aShowFields, RestUtils::GetFieldList($sSelectedClass, $aParams, 'output_fields', false));
+				}
+
+                if (!RestUtils::HasRequestedAllOutputFields($sShowFields) && count($aShowFields) == 1) {
+	                $aFields = $aShowFields[$sClass];
+	                //Id is not a valid attribute to optimize
+	                if (in_array('id', $aFields)) {
+	                    unset($aFields[array_search('id', $aFields)]);
+	                }
+	                $aAttToLoad = array($oObjectSet->GetClassAlias() => $aFields);
+	                $oObjectSet->OptimizeColumnLoad($aAttToLoad);
+                }
+
+				while ($oObject = $oObjectSet->Fetch()) {
+					$oResult->AddObject(0, '', $oObject, $aShowFields, RestUtils::HasRequestedExtendedOutput($sShowFields));
 				}
 				$oResult->message = "Found: ".$oObjectSet->Count();
 			}
diff --git a/tests/php-unit-tests/unitary-tests/webservices/RestTest.php b/tests/php-unit-tests/unitary-tests/webservices/RestTest.php
index 6b1c6848a3..f96545ab97 100644
--- a/tests/php-unit-tests/unitary-tests/webservices/RestTest.php
+++ b/tests/php-unit-tests/unitary-tests/webservices/RestTest.php
@@ -142,6 +142,158 @@ public function testCoreApiGet(){
 		$this->assertJsonStringEqualsJsonString($sExpectedJsonOuput, $sJSONOutput);
 	}
 
+
+	public function testCoreApiGet_Select2SubClasses(){
+		// Create ticket
+		$description = date('dmY H:i:s');
+		$iIdCaller = $this->CreatePerson(1)->GetKey();
+		$oUserRequest = $this->CreateSampleTicket($description, 'UserRequest', $iIdCaller);
+		$oChange = $this->CreateSampleTicket($description, 'Change', $iIdCaller);
+		$iIdUserRequest = $oUserRequest->GetKey();
+		$iIdChange = $oChange->GetKey();
+
+		$sJSONOutput = $this->CallCoreRestApi_Internally(<<<JSON
+{
+   "operation": "core/get",
+   "class": "UserRequest, Change",
+   "key": "SELECT UserRequest WHERE id=$iIdUserRequest UNION SELECT Change WHERE id=$iIdChange",
+   "output_fields": "id, description, outage"
+}
+JSON);
+
+		$sExpectedJsonOuput = <<<JSON
+{
+    "code": 0,
+    "message": "Found: 2",
+    "objects": {
+        "UserRequest::$iIdUserRequest": {
+            "class": "UserRequest",
+            "code": 0,
+            "fields": {
+                "description": "<p>$description</p>",
+                "id": "$iIdUserRequest"
+            },
+            "key": "$iIdUserRequest",
+            "message": ""
+        },       
+         "Change::$iIdChange": {
+            "class": "Change",
+            "code": 0,
+            "fields": {
+                "description": "<p>$description</p>",
+                "id": "$iIdChange",
+                "outage": "no"
+            },
+            "key": "$iIdChange",
+            "message": ""
+        }
+    }
+}
+JSON;
+		$this->assertJsonStringEqualsJsonString($sExpectedJsonOuput, $sJSONOutput);
+	}
+
+
+	public function testCoreApiGet_SelectTicketAndPerson(){
+		// Create ticket
+		$description = date('dmY H:i:s');
+		$iIdCaller = $this->CreatePerson(1)->GetKey();
+		$oUserRequest = $this->CreateSampleTicket($description, 'UserRequest', $iIdCaller);
+		$iIdUserRequest = $oUserRequest->GetKey();
+
+		$sJSONOutput = $this->CallCoreRestApi_Internally(<<<JSON
+{
+   "operation": "core/get",
+   "class": "UserRequest, Change",
+   "key": "SELECT UR, P FROM UserRequest AS UR JOIN Person AS P ON UR.caller_id = P.id WHERE UR.id=$iIdUserRequest ",
+   "output_fields": "id, title, description, name, email"
+}
+JSON);
+
+		$sExpectedJsonOuput = <<<JSON
+{
+    "code": 0,
+    "message": "Found: 1",
+    "objects": [{
+	        "UR": {
+	            "class": "UserRequest",
+	            "code": 0,
+	            "fields": {
+	                "description": "<p>$description</p>",
+	                "id": "$iIdUserRequest",                
+	                "title": "Houston, got a problem"
+	            },
+	            "key": "$iIdUserRequest",
+	            "message": ""
+	        },       
+            "P": {
+                "class": "Person",
+                "code": 0,
+                "fields": {
+                    "email": "",
+                    "id": "$iIdCaller",
+                    "name": "Person_1"
+                },
+            "key": "$iIdCaller",
+            "message": ""
+        }
+    }]
+}
+JSON;
+		$this->assertJsonStringEqualsJsonString($sExpectedJsonOuput, $sJSONOutput);
+	}
+
+	public function testCoreApiGetWithUnionAndDifferentOutputFields(){
+		// Create ticket
+		$description = date('dmY H:i:s');
+		$oUserRequest = $this->CreateSampleTicket($description);
+		$oChange = $this->CreateSampleTicket($description, 'Change');
+		$iUserRequestId = $oUserRequest->GetKey();
+		$sUserRequestRef = $oUserRequest->Get('ref');
+		$iChangeId = $oChange->GetKey();
+		$sChangeRef = $oChange->Get('ref');
+
+		$sJSONOutput = $this->CallCoreRestApi_Internally(<<<JSON
+{
+   "operation": "core/get",
+   "class": "Ticket",
+   "key": "SELECT UserRequest WHERE id=$iUserRequestId UNION SELECT Change WHERE id=$iChangeId",
+   "output_fields": "Ticket:ref;UserRequest:ref,status,origin;Change:ref,status,outage"
+}
+JSON);
+
+		$sExpectedJsonOuput = <<<JSON
+{
+    "code": 0,
+    "message": "Found: 2",
+    "objects": {
+    	"Change::$iChangeId": {
+            "class": "Change",
+            "code": 0,
+            "fields": {
+            	"outage": "no",
+                "ref": "$sChangeRef",
+                "status": "new"
+            },
+            "key": "$iChangeId",
+            "message": ""
+        },
+        "UserRequest::$iUserRequestId": {
+            "class": "UserRequest",
+            "code": 0,
+            "fields": {
+            	"origin": "phone",
+                "ref": "$sUserRequestRef",
+                "status": "new"
+            },
+            "key": "$iUserRequestId",
+            "message": ""
+        }
+    }
+}
+JSON;
+		$this->assertJsonStringEqualsJsonString($sExpectedJsonOuput, $sJSONOutput);
+	}
 	public function testCoreApiCreate()
 	{
 		// Create ticket
@@ -253,12 +405,13 @@ public function testCoreApiDelete()
 	//
 	////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-	private function CreateSampleTicket($description)
+	private function CreateSampleTicket($description, $sType = 'UserRequest', $iIdCaller = null)
 	{
-		$oTicket = $this->createObject('UserRequest', [
+		$oTicket = $this->createObject($sType, [
 			'org_id' => $this->getTestOrgId(),
 			"title" => "Houston, got a problem",
-			"description" => $description
+			"description" => $description,
+			"caller_id" => $iIdCaller,
 		]);
 		return $oTicket;
 	}
diff --git a/tests/php-unit-tests/unitary-tests/webservices/RestUtilsTest.php b/tests/php-unit-tests/unitary-tests/webservices/RestUtilsTest.php
new file mode 100644
index 0000000000..779c93819f
--- /dev/null
+++ b/tests/php-unit-tests/unitary-tests/webservices/RestUtilsTest.php
@@ -0,0 +1,110 @@
+<?php
+
+namespace Combodo\iTop\Test\UnitTest\Webservices;
+
+use Combodo\iTop\Test\UnitTest\ItopDataTestCase;
+use MetaModel;
+use RestUtils;
+use Ticket;
+use UserRequest;
+
+
+class RestUtilsTest extends ItopDataTestCase
+{
+	public function testGetFieldListForSingleClass(): void
+	{
+		$aList = RestUtils::GetFieldList(Ticket::class, (object) ['output_fields' => 'ref,start_date,end_date'], 'output_fields');
+		$this->assertSame([Ticket::class => ['ref', 'start_date', 'end_date']], $aList);
+	}
+
+	public function testGetFieldListForSingleClassWithInvalidFieldNameFails(): void
+	{
+		$this->expectException(\Exception::class);
+		$this->expectExceptionMessage('output_fields: invalid attribute code \'something\' for class \'Ticket\'');
+		$aList = RestUtils::GetFieldList(Ticket::class, (object) ['output_fields' => 'ref,something'], 'output_fields');
+		$this->assertSame([Ticket::class => ['ref', 'start_date', 'end_date']], $aList);
+	}
+
+	public function testGetFieldListWithAsteriskOnParentClass(): void
+	{
+		$aList = RestUtils::GetFieldList(Ticket::class, (object) ['output_fields' => '*'], 'output_fields');
+		$this->assertArrayHasKey(Ticket::class, $aList);
+		$this->assertContains('operational_status', $aList[Ticket::class]);
+		$this->assertNotContains('status', $aList[Ticket::class], 'Representation of Class Ticket should not contain status, since it is defined by children');
+	}
+
+	public function testGetFieldListWithAsteriskPlusOnParentClass(): void
+	{
+		$aList = RestUtils::GetFieldList(Ticket::class, (object) ['output_fields' => '*+'], 'output_fields');
+		$this->assertArrayHasKey(Ticket::class, $aList);
+		$this->assertArrayHasKey(UserRequest::class, $aList);
+		$this->assertContains('operational_status', $aList[Ticket::class]);
+		$this->assertContains('status', $aList[UserRequest::class]);
+	}
+
+	public function testGetFieldListForMultipleClasses(): void
+	{
+		$aList = RestUtils::GetFieldList(Ticket::class, (object) ['output_fields' => 'Ticket:ref,start_date,end_date;UserRequest:ref,status'], 'output_fields');
+		$this->assertArrayHasKey(Ticket::class, $aList);
+		$this->assertArrayHasKey(UserRequest::class, $aList);
+		$this->assertContains('ref', $aList[Ticket::class]);
+		$this->assertContains('end_date', $aList[Ticket::class]);
+		$this->assertNotContains('status', $aList[Ticket::class]);
+		$this->assertContains('status', $aList[UserRequest::class]);
+		$this->assertNotContains('end_date', $aList[UserRequest::class]);
+	}
+
+	public function testGetFieldListForMultipleClassesWithInvalidFieldNameFails(): void
+	{
+		$this->expectException(\Exception::class);
+		$this->expectExceptionMessage('output_fields: invalid attribute code \'something\'');
+		RestUtils::GetFieldList(Ticket::class, (object) ['output_fields' => 'Ticket:ref;UserRequest:ref,something'], 'output_fields');
+	}
+
+
+	public function testGetFieldListForMultipleClassesWithInvalidFieldName(): void
+	{
+		$aList = RestUtils::GetFieldList(Ticket::class, (object) ['output_fields' => 'ref, something'], 'output_fields', false);
+		$this->assertContains('ref', $aList[Ticket::class]);
+		$this->assertNotContains('something', $aList[Ticket::class]);
+	}
+
+
+	/**
+	 * @dataProvider extendedOutputDataProvider
+	 */
+	public function testIsExtendedOutputRequest(bool $bExpected, string $sFields): void
+	{
+		$this->assertSame($bExpected, RestUtils::HasRequestedExtendedOutput($sFields));
+	}
+
+	/**
+	 * @dataProvider allFieldsOutputDataProvider
+	 */
+	public function testIsAllFieldsOutputRequest(bool $bExpected, string $sFields): void
+	{
+		$this->assertSame($bExpected, RestUtils::HasRequestedAllOutputFields($sFields));
+	}
+
+	public function extendedOutputDataProvider(): array
+	{
+		return [
+			[false, 'ref,start_date,end_date'],
+			[false, '*'],
+			[true, '*+'],
+			[false, 'Ticket:ref'],
+			[true, 'Ticket:ref;UserRequest:ref'],
+		];
+	}
+
+	public function allFieldsOutputDataProvider(): array
+	{
+		return [
+			[false, 'ref,start_date,end_date'],
+			[true, '*'],
+			[true, '*+'],
+			[false, 'Ticket:ref'],
+			[false, 'Ticket:ref;UserRequest:ref'],
+		];
+	}
+}
\ No newline at end of file