Bug 20446 cannot create protected or private interfaces [code manipulation]
F3 the spec allows creating protected or private nested interfaces but eclipse disallows it (the new interface wizard)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/wizards/NewTypeWizardPage.java
IType workingCopy= (IType) EditorUtility.getWorkingCopy(enclosingType);
				if (workingCopy != null) {
					enclosingType= workingCopy;
				}
	
				ICompilationUnit parentCU= enclosingType.getCompilationUnit();
				imports= new ImportsManager(parentCU);
	
				
				IType[] topLevelTypes= parentCU.getTypes();
				for (int i= 0; i < topLevelTypes.length; i++) {
					imports.addImport(topLevelTypes[i].getFullyQualifiedName('.'));
				}
				
				lineDelimiter= StubUtility.getLineDelimiterUsed(enclosingType);
				StringBuffer content= new StringBuffer();
				
				if (PreferenceConstants.getPreferenceStore().getBoolean(PreferenceConstants.CODEGEN_ADD_COMMENTS)) {
					String comment= getTypeComment(parentCU, lineDelimiter);
					if (comment != null) {
						content.append(comment);
						content.append(lineDelimiter);
					}
				}
				content.append(constructTypeStub(imports, lineDelimiter));
				IJavaElement[] elems= enclosingType.getChildren();
				IJavaElement sibling= elems.length > 0 ? elems[0] : null;