Bug 47838 Make refactoring menu selection sensitive in editor [refactoring]
M5 Currently all refactoring actions are enabled in the editor's context menu. Make them selection dependent. Check if code resolve might be enough (no need to create an AST).
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/ModifyParametersAction.java
private CompilationUnitEditor fEditor;
	
	/**
	 * Note: This constructor is for internal use only. Clients should not call this constructor.
	 */
	public ModifyParametersAction(CompilationUnitEditor editor) {
		this(editor.getEditorSite());
		fEditor= editor;
		setEnabled(SelectionConverter.canOperateOn(fEditor));
	}
	/**