Update the node's configuration

        Args:

            node_id (string): ID of the node to be updated.
            version (int): The version number of the node object being
                updated. This is required to avoid conflicting writes.
            node_spec (dict): Configuration settings to update. Any values
                not provided will be removed. Default: ``None``

        Returns:
            `True` if the request went through.

        Raises:
            :py:class:`docker.errors.APIError`
                If the server returns an error.

        Example:

            >>> node_spec = {'Availability': 'active',
                         'Name': 'node-name',
                         'Role': 'manager',
                         'Labels': {'foo': 'bar'}
                        }
            >>> client.update_node(node_id='24ifsmvkjbyhk', version=8,
                node_spec=node_spec)

def update_node(self, node_id, version, node_spec=None):
        """
        Update the node's configuration

        Args:

            node_id (string): ID of the node to be updated.
            version (int): The version number of the node object being
                updated. This is required to avoid conflicting writes.
            node_spec (dict): Configuration settings to update. Any values
                not provided will be removed. Default: ``None``

        Returns:
            `True` if the request went through.

        Raises:
            :py:class:`docker.errors.APIError`
                If the server returns an error.

        Example:

            >>> node_spec = {'Availability': 'active',
                         'Name': 'node-name',
                         'Role': 'manager',
                         'Labels': {'foo': 'bar'}
                        }
            >>> client.update_node(node_id='24ifsmvkjbyhk', version=8,
                node_spec=node_spec)

        """
        url = self._url('/nodes/{0}/update?version={1}', node_id, str(version))
        res = self._post_json(url, data=node_spec)
        self._raise_for_status(res)
        return True