Bug 15527 JavaCore constants should be used is favor of hard-coded strings
the following classes should use constants defined in JavaCode rather than hard-coded strings StubUtility CodeFormatterUtil CompilationUnitEditor JavaCodeScanner JavaCompiletionProcessor
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
public void addTextConverter(ITextConverter textConverter) {
			if (fTextConverters == null) {
				fTextConverters= new ArrayList(1);
				fTextConverters.add(textConverter);
			} else if (!fTextConverters.contains(textConverter))
				fTextConverters.add(textConverter);
		}
		
		public void removeTextConverter(ITextConverter textConverter) {
			if (fTextConverters != null) {
				fTextConverters.remove(textConverter);
				if (fTextConverters.size() == 0)
					fTextConverters= null;
			}
		}
		
		/*
		 * @see TextViewer#customizeDocumentCommand(DocumentCommand)
		 */
		protected void customizeDocumentCommand(DocumentCommand command) {
			super.customizeDocumentCommand(command);
			if (fTextConverters != null) {
				for (Iterator e = fTextConverters.iterator(); e.hasNext();)
					((ITextConverter) e.next()).customizeDocumentCommand(getDocument(), command);
			}
		}
		
		public IVerticalRuler getVerticalRuler() {
			return fCachedVerticalRuler;
		}