fix some warnings

Author: lucasamoroso

instrumentation/kamon-armeria/src/main/scala/kamon/instrumentation/armeria/client/ArmeriaHttpClientInstrumentation.scala

@@ -16,8 +16,9 @@
 package kamon.instrumentation.armeria.client
 
 import com.linecorp.armeria.client.{ClientBuilder, HttpClient}
+import com.typesafe.config.Config
 import kamon.Kamon
-import kamon.instrumentation.armeria.converters.JavaConverters
+import kamon.instrumentation.armeria.converters.JavaConverter
 import kamon.instrumentation.http.HttpClientInstrumentation
 import kanela.agent.api.instrumentation.InstrumentationBuilder
 import kanela.agent.libs.net.bytebuddy.asm.Advice
@@ -29,12 +30,12 @@ class ArmeriaHttpClientInstrumentation extends InstrumentationBuilder {
 
 class ArmeriaHttpClientBuilderAdvisor
 
-object ArmeriaHttpClientBuilderAdvisor extends JavaConverters {
-  lazy val httpClientConfig = Kamon.config().getConfig("kamon.instrumentation.armeria.client")
+object ArmeriaHttpClientBuilderAdvisor extends JavaConverter {
+  lazy val httpClientConfig: Config = Kamon.config().getConfig("kamon.instrumentation.armeria.client")
 
   @Advice.OnMethodExit(suppress = classOf[Throwable])
   def addKamonDecorator(@Advice.This builder: ClientBuilder): Unit = {
-    val clientInstrumentation = HttpClientInstrumentation.from(httpClientConfig, "armeria.http.client");
+    val clientInstrumentation = HttpClientInstrumentation.from(httpClientConfig, "armeria.http.client")
     builder.decorator(toJavaFunction((delegate: HttpClient) => new ArmeriaHttpClientDecorator(delegate, clientInstrumentation)))
   }
 }

instrumentation/kamon-armeria/src/main/scala/kamon/instrumentation/armeria/converters/JavaConverters.scala renamed to instrumentation/kamon-armeria/src/main/scala/kamon/instrumentation/armeria/converters/JavaConverter.scala

@@ -5,7 +5,7 @@ import java.util.function.{Function => JFunction}
 /**
   * Only because scala-2.11 compatibility issues
   */
-trait JavaConverters {
+trait JavaConverter {
   implicit def toJavaFunction[A, B](f: Function1[A, B]): JFunction[A, B] = new JFunction[A, B] {
     override def apply(a: A): B = f(a)
   }

instrumentation/kamon-armeria/src/main/scala/kamon/instrumentation/armeria/converters/KamonArmeriaMessageConverter.scala

@@ -21,7 +21,6 @@ import kamon.context.HttpPropagation.HeaderWriter
 import kamon.instrumentation.http.HttpMessage
 
 import scala.collection.JavaConverters.iterableAsScalaIterableConverter
-import scala.collection.immutable.Map
 import scala.collection.{JavaConverters, mutable}
 
 object KamonArmeriaMessageConverter {
@@ -60,7 +59,7 @@ object KamonArmeriaMessageConverter {
 
     override def read(header: String): Option[String] = Option(request.headers().get(header))
 
-    override def readAll: Map[String, String] = {
+    override def readAll(): Map[String, String] = {
       JavaConverters
         .asScalaIteratorConverter(request.headers().iterator())
         .asScala
@@ -83,7 +82,7 @@ object KamonArmeriaMessageConverter {
       _headers += (header -> value)
     }
 
-    override def build: HttpRequest = {
+    override def build(): HttpRequest = {
       val newHeadersMap = request.headers.toBuilder
       _headers.foreach { case (key, value) => newHeadersMap.add(key, value) }
       request.withHeaders(newHeadersMap)

instrumentation/kamon-armeria/src/main/scala/kamon/instrumentation/armeria/server/ArmeriaHttpServerInstrumentation.scala

@@ -19,8 +19,9 @@ import java.util
 
 import com.linecorp.armeria.common.HttpStatus
 import com.linecorp.armeria.server._
+import com.typesafe.config.Config
 import kamon.Kamon
-import kamon.instrumentation.armeria.converters.JavaConverters
+import kamon.instrumentation.armeria.converters.JavaConverter
 import kamon.instrumentation.armeria.server.ArmeriaHttpServerDecorator.REQUEST_HANDLER_TRACE_KEY
 import kamon.instrumentation.armeria.server.InternalState.ServerBuilderInternalState
 import kamon.instrumentation.http.HttpServerInstrumentation
@@ -45,8 +46,8 @@ class ArmeriaServerBuilderAdvisor
   * After enter to <a href="https://github.com/line/armeria/blob/master/core/src/main/java/com/linecorp/armeria/server/ServerBuilder.java">build()</a>
   * some things are done with the ports field, so we aren't entirely sure that this ports are gonna to be final
   */
-object ArmeriaServerBuilderAdvisor extends JavaConverters {
-  lazy val httpServerConfig = Kamon.config().getConfig("kamon.instrumentation.armeria.server")
+object ArmeriaServerBuilderAdvisor extends JavaConverter {
+  lazy val httpServerConfig: Config = Kamon.config().getConfig("kamon.instrumentation.armeria.server")
 
   @Advice.OnMethodEnter
   def addKamonDecorator(@Advice.This builder: ServerBuilder): Unit = {
@@ -66,7 +67,7 @@ object ArmeriaServerBuilderAdvisor extends JavaConverters {
 class HandleNotFoundMethodAdvisor
 
 object HandleNotFoundMethodAdvisor {
-  lazy val unhandledOperationName = Kamon.config().getConfig("kamon.instrumentation.armeria.server").getString("tracing.operations.unhandled")
+  lazy val unhandledOperationName: String = Kamon.config().getConfig("kamon.instrumentation.armeria.server").getString("tracing.operations.unhandled")
 
   /**
     * When an HttpStatusException is thrown in {@link com.linecorp.armeria.server.FallbackService.handleNotFound( )} is because the route doesn't  exist