public com.google.protobuf.ByteString getRequestIdBytes() {
      java.lang.Object ref = requestId_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        requestId_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Optional. The request ID must be a valid UUID with the exception that zero
UUID is not supported (00000000-0000-0000-0000-000000000000).
</pre>

<code>string request_id = 4 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for requestId.
java-vmwareengine/proto-google-cloud-vmwareengine-v1/src/main/java/com/google/cloud/vmwareengine/v1/CreatePrivateCloudRequest.java