Display a node as expanded

        :param item: The item to show expanded
        :param open_all: Whether all child nodes should be recursively
                         expanded.

def expand_item(self, item, open_all=True):
        """Display a node as expanded

        :param item: The item to show expanded
        :param open_all: Whether all child nodes should be recursively
                         expanded.
        """
        self.expand_row(self._view_path_for(item), open_all)