refactor: add copy constructor to request context

Author: aaron-steinfeld

grpc-context-utils/src/main/java/org/hypertrace/core/grpcutils/context/RequestContext.java

@@ -33,6 +33,12 @@ public class RequestContext {
   public static final Context.Key<RequestContext> CURRENT = Context.key("request_context");
   private static final JwtParser JWT_PARSER = new JwtParser();
 
+  public RequestContext() {}
+
+  public RequestContext(RequestContext otherContext) {
+    this.headers.putAll(otherContext.headers);
+  }
+
   public static RequestContext forTenantId(String tenantId) {
     return new RequestContext()
         .put(RequestContextConstants.TENANT_ID_HEADER_KEY, tenantId)

grpc-context-utils/src/test/java/org/hypertrace/core/grpcutils/context/RequestContextTest.java

@@ -49,6 +49,15 @@ void testGetRequestHeaders() {
         requestHeaders);
   }
 
+  @Test
+  void testCopyConstructor() {
+    RequestContext originalContext = new RequestContext();
+    originalContext.put(RequestContextConstants.AUTHORIZATION_HEADER, TEST_AUTH_HEADER);
+    originalContext.put("x-some-tenant-header", "v1");
+
+    assertEquals(originalContext, new RequestContext(originalContext));
+  }
+
   @Test
   void testCreateForTenantId() {
     RequestContext requestContext = RequestContext.forTenantId(TENANT_ID);