public JobFlowInstancesDetail withMasterInstanceId(String masterInstanceId) {
        setMasterInstanceId(masterInstanceId);
        return this;
    }
<p>
The Amazon EC2 instance identifier of the master node.
</p>

@param masterInstanceId
       The Amazon EC2 instance identifier of the master node.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-emr/src/main/java/com/amazonaws/services/elasticmapreduce/model/JobFlowInstancesDetail.java