Bug 167170 [Markers] Need to check for duplicate filter names
M3 It is currently possible to enter duplicate filter names
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/DialogMarkerFilter.java
layout.marginHeight = 0;
			radio.dispose();
			composite.setLayout(layout);
			selectButton = createButton(composite, SELECT_WORKING_SET_ID,
					MarkerMessages.filtersDialog_workingSetSelect, false);
		}
		/**
		 * Returns wether or not a working set filter should be used
		 * 
		 * @return true=a working set filter should be used false=a working set
		 *         filter should not be used
		 */
		boolean getSelection() {
			return button.getSelection();
		}
		/**
		 * Returns the selected working set filter or null if none is selected.
		 * 
		 * @return the selected working set filter or null if none is selected.
		 */
		IWorkingSet getWorkingSet() {
			return (IWorkingSet) button.getData();
		}
		/**
		 * Sets the working set filter selection.
		 * 
		 * @param selected
		 *            true=a working set filter should be used false=no working
		 *            set filter should be used
		 */