public Builder mergeWorkflow(com.google.cloud.workflows.v1beta.Workflow value) {
      if (workflowBuilder_ == null) {
        if (((bitField0_ & 0x00000001) != 0)
            && workflow_ != null
            && workflow_ != com.google.cloud.workflows.v1beta.Workflow.getDefaultInstance()) {
          getWorkflowBuilder().mergeFrom(value);
        } else {
          workflow_ = value;
        }
      } else {
        workflowBuilder_.mergeFrom(value);
      }
      if (workflow_ != null) {
        bitField0_ |= 0x00000001;
        onChanged();
      }
      return this;
    }
<pre>
Required. Workflow to be updated.
</pre>

<code>
.google.cloud.workflows.v1beta.Workflow workflow = 1 [(.google.api.field_behavior) = REQUIRED];
</code>
java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/UpdateWorkflowRequest.java