public Cluster withPlacementGroups(java.util.Collection<PlacementGroupConfig> placementGroups) {
        setPlacementGroups(placementGroups);
        return this;
    }
<p>
Placement group configured for an Amazon EMR cluster.
</p>

@param placementGroups
       Placement group configured for an Amazon EMR cluster.
@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/Cluster.java