public void setInstanceCount(Integer instanceCount) {
        this.instanceCount = instanceCount;
    }
<p>
The number of Amazon EC2 instances in the cluster. If the value is 1, the same instance serves as both the master
and core and task node. If the value is greater than 1, one instance is the master node and all others are core
and task nodes.
</p>

@param instanceCount
       The number of Amazon EC2 instances in the cluster. If the value is 1, the same instance serves as both the
       master and core and task node. If the value is greater than 1, one instance is the master node and all
       others are core and task nodes.
aws-java-sdk-emr/src/main/java/com/amazonaws/services/elasticmapreduce/model/JobFlowInstancesDetail.java