Bug 14444 java editor refers to internal jcore classes
ClassFileEditor CompilationUnitDocumentProvider JavaMarkerAnnotation
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitDocumentProvider.java
public int getId() {
				return fProblem.getID();
			}
			/*
			 * @see IProblemAnnotation#isProblem()
			 */
			public boolean isProblem() {
				return true;
			}
			
			/*
			 * @see IProblemAnnotation#isRelevant()
			 */
			public boolean isRelevant() {
				return true;
			}
			
			/*
			 * @see IProblemAnnotation#hasOverlay()
			 */
			public boolean hasOverlay() {
				return false;
			}
			
			/*
			 * @see IProblemAnnotation#addOverlaid(IProblemAnnotation)
			 */
			public void addOverlaid(IProblemAnnotation annotation) {
				if (fOverlaids == null)
					fOverlaids= new ArrayList(1);