code: public void performMerge( GrayS32 pixelToRegion ,
  							  GrowQueue_I32 regionMemberCount ) {
  		// update member counts
  		flowIntoRootNode(regionMemberCount);
  
  		// re-assign the number of the root node and trim excessive nodes from the lists
  		setToRootNodeNewID(regionMemberCount);
  
  		// change the labels in the pixelToRegion image
  		BinaryImageOps.relabel(pixelToRegion, mergeList.data);
  	}
docs: Merges regions together and updates the provided data structures for said changes.
  
  @param pixelToRegion (Input/Output) Image used to convert pixel location in region ID.  Modified.
  @param regionMemberCount (Input/Output) List containing how many pixels belong to each region.  Modified.