code: public java.util.List<InstanceGroup> getInstanceGroups() {
          if (instanceGroups == null) {
              instanceGroups = new com.amazonaws.internal.SdkInternalList<InstanceGroup>();
          }
          return instanceGroups;
      }
docs: <p>
  The list of instance groups for the cluster and given filters.
  </p>
  
  @return The list of instance groups for the cluster and given filters.