code: public final static void addGroup(final GroupingNotation notation, final int position,
  			final HELM2Notation helm2notation) {
  		helm2notation.getListOfGroupings().add(position, notation);
  	}
docs: method to add a group to the grouping section of the HELM2Notation
  
  @param notation
  new group
  @param position
  position of the new group
  @param helm2notation
  input HELM2Notation