public ResponseMessage create() {
            final ResponseResult responseResult = new ResponseResult(result, bulked);
            // skip null values
            if (code == null && statusMessage == null) {
                return new ResponseMessage(null, responseResult);
            }
            final ResponseStatus responseStatus = new ResponseStatus(code, statusMessage, exception);
            return new ResponseMessage(responseStatus, responseResult);
        }
The model for a response message that is sent to the server beginning in 4.0.0. ResponseMessage is designed to be
streamed back the client in parts so depending on the state of the transfer, certain parts may be null at different
times.

@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-util/src/main/java/org/apache/tinkerpop/gremlin/util/message/ResponseMessage.java