Bug 81196 Can't search for References, ... to an ITypeParameter [search]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/FindWriteReferencesInHierarchyAction.java
/**
	 * Creates a new <code>FindWriteReferencesInHierarchyAction</code>. The action 
	 * requires that the selection provided by the site's selection provider is of type 
	 * <code>org.eclipse.jface.viewers.IStructuredSelection</code>.
	 * 
	 * @param site the site providing context information for this action
	 */
	public FindWriteReferencesInHierarchyAction(IWorkbenchSite site) {
		super(site, SearchMessages.getString("Search.FindWriteReferencesInHierarchyAction.label"), new Class[] {IField.class, ILocalVariable.class } ); 
		setToolTipText(SearchMessages.getString("Search.FindWriteReferencesInHierarchyAction.tooltip")); 
		PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IJavaHelpContextIds.FIND_WRITE_REFERENCES_IN_HIERARCHY_ACTION);
	}
	/**
	 * Note: This constructor is for internal use only. Clients should not call this constructor.
	 */
	public FindWriteReferencesInHierarchyAction(JavaEditor editor) {
		super(editor, SearchMessages.getString("Search.FindWriteReferencesInHierarchyAction.label"), new Class[] {IField.class, ILocalVariable.class } ); 
		setToolTipText(SearchMessages.getString("Search.FindWriteReferencesInHierarchyAction.tooltip")); 
		PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IJavaHelpContextIds.FIND_WRITE_REFERENCES_IN_HIERARCHY_ACTION);
	}
	int getLimitTo() {
		return IJavaSearchConstants.WRITE_ACCESSES;
	}
	String getOperationUnavailableMessage() {
		return SearchMessages.getString("JavaElementAction.operationUnavailable.field"); 
	}
}