code: public final void createRoleGhant(final AbstractOrderedLayout roleSummaryLayoutTabsheet, final Collection<T> assignmentList) {
  
  		final Comparator<T> compare = getComparator();
  
  		final List<T> list = assignmentList.stream().filter(
  				(final T x) -> new DateTime(getStepMapping().getFromDate(x).getTime()).getYear() > FILTER_DATA_BEFORE_YEAR)
  				.collect(Collectors.toList());
  
  		Collections.sort(list, compare);
  
  		final Gantt createGantt = createGenericGantt(list, getRoleMapping(), getStepMapping());
  		roleSummaryLayoutTabsheet.addComponent(createGantt);
  		roleSummaryLayoutTabsheet.setExpandRatio(createGantt, ContentRatio.GRID);
  
  	}
docs: Creates the role ghant.
  
  @param roleSummaryLayoutTabsheet the role summary layout tabsheet
  @param assignmentList            the assignment list