Bug 75711 AstProvider should not create AST if requested by SelectionListenerWithASTManager
3.1 M2 If SelectionListenerWithASTManager waits for an AST and the editor closes we should not create an AST for that one but return null instead.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
/**
		 * {@inheritDoc}
		 */
		public void setToDefault(String name) {
			throw new UnsupportedOperationException();
		}
		/**
		 * {@inheritDoc}
		 */
		public void setValue(String name, double value) {
			throw new UnsupportedOperationException();
		}
		/**
		 * {@inheritDoc}
		 */
		public void setValue(String name, float value) {
			throw new UnsupportedOperationException();
		}
		/**
		 * {@inheritDoc}
		 */
		public void setValue(String name, int value) {
			throw new UnsupportedOperationException();
		}
		/**
		 * {@inheritDoc}
		 */
		public void setValue(String name, long value) {
			throw new UnsupportedOperationException();
		}