code: public void setPlacementGroups(java.util.Collection<PlacementGroup> placementGroups) {
          if (placementGroups == null) {
              this.placementGroups = null;
              return;
          }
  
          this.placementGroups = new com.amazonaws.internal.SdkInternalList<PlacementGroup>(placementGroups);
      }
docs: <p>
  Information about the placement groups.
  </p>
  
  @param placementGroups
  Information about the placement groups.