Bug 51653 [navigation] Quick Outline: Should also show interface members
I200402102000 We should consider showing the inherited members for interfaces at least when the target type is an interface itself.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/JavaOutlineInformationControl.java
return fShowInheritedMembers;
		}
		
		public void toggleShowInheritedMembers() {
			fShowInheritedMembers= !fShowInheritedMembers;
			getTreeViewer().refresh();
		}
		
		/**
		 * {@inheritDoc}
		 */
		public Object[] getChildren(Object element) {
			if (fShowInheritedMembers && element instanceof IType) {
				IType type= (IType)element;
				if (type.getDeclaringType() == null) {
					ITypeHierarchy th= getSuperTypeHierarchy(type);
					if (th != null) {
						List children= new ArrayList();
						IType[] superClasses= th.getAllSuperclasses(type);
						children.addAll(Arrays.asList(super.getChildren(type)));
						for (int i= 0, scLength= superClasses.length; i < scLength; i++)
							children.addAll(Arrays.asList(super.getChildren(superClasses[i])));
						return children.toArray();
					}
				}
			}
			return super.getChildren(element);
		}
		
		private ITypeHierarchy getSuperTypeHierarchy(IType type) {