Unblock UseExisting conflict policy for Nexux WorkflowRunOperation (#2440)

Author: rodrigozhou

temporal-sdk/src/main/java/io/temporal/internal/common/InternalUtils.java

@@ -22,11 +22,9 @@
 
 import com.google.common.base.Defaults;
 import io.nexusrpc.Header;
-import io.nexusrpc.handler.HandlerException;
 import io.nexusrpc.handler.ServiceImplInstance;
 import io.temporal.api.common.v1.Callback;
 import io.temporal.api.enums.v1.TaskQueueKind;
-import io.temporal.api.enums.v1.WorkflowIdConflictPolicy;
 import io.temporal.api.taskqueue.v1.TaskQueue;
 import io.temporal.client.OnConflictOptions;
 import io.temporal.client.WorkflowOptions;
@@ -37,7 +35,6 @@
 import io.temporal.internal.client.NexusStartWorkflowRequest;
 import java.util.Arrays;
 import java.util.Map;
-import java.util.Objects;
 import java.util.TreeMap;
 import java.util.stream.Collectors;
 import org.slf4j.Logger;
@@ -155,16 +152,6 @@ public static WorkflowStub createNexusBoundStub(
             .setAttachCompletionCallbacks(true)
             .build());
 
-    // TODO(klassenq) temporarily blocking conflict policy USE_EXISTING.
-    if (Objects.equals(
-        WorkflowIdConflictPolicy.WORKFLOW_ID_CONFLICT_POLICY_USE_EXISTING,
-        options.getWorkflowIdConflictPolicy())) {
-      throw new HandlerException(
-          HandlerException.ErrorType.INTERNAL,
-          new IllegalArgumentException(
-              "Workflow ID conflict policy UseExisting is not supported for Nexus WorkflowRunOperation."),
-          HandlerException.RetryBehavior.NON_RETRYABLE);
-    }
     return stub.newInstance(nexusWorkflowOptions.build());
   }
 

temporal-sdk/src/test/java/io/temporal/workflow/nexus/WorkflowHandleUseExistingOnConflictCancelTest.java

@@ -38,7 +38,6 @@
 import java.util.UUID;
 import org.junit.*;
 
-@Ignore("Skipping until we can support USE_EXISTING")
 public class WorkflowHandleUseExistingOnConflictCancelTest {
   @Rule
   public SDKTestWorkflowRule testWorkflowRule =

temporal-sdk/src/test/java/io/temporal/workflow/nexus/WorkflowHandleUseExistingOnConflictTest.java

@@ -36,7 +36,6 @@
 import java.util.UUID;
 import org.junit.*;
 
-@Ignore("Skipping until we can support USE_EXISTING")
 public class WorkflowHandleUseExistingOnConflictTest {
   @Rule
   public SDKTestWorkflowRule testWorkflowRule =