public void setSecurityGroup(String securityGroup) {
        this.securityGroup = securityGroup;
    }
<p>
The identifier (ID) of the cluster's security group.
</p>

@param securityGroup
       The identifier (ID) of the cluster's security group.
aws-java-sdk-cloudhsmv2/src/main/java/com/amazonaws/services/cloudhsmv2/model/Cluster.java