public void setMasterInstanceType(String masterInstanceType) {
        this.masterInstanceType = masterInstanceType;
    }
<p>
The Amazon EC2 master node instance type.
</p>

@param masterInstanceType
       The Amazon EC2 master node instance type.
aws-java-sdk-emr/src/main/java/com/amazonaws/services/elasticmapreduce/model/JobFlowInstancesDetail.java