'Check if a node exists.
If a watch is provided, it will be left on the node with the
given path. The watch will be triggered by a successful
operation that creates/deletes the node or sets the data on the
node.
:param path: Path of node.
:param watch: Optional watch callback to set for future changes
to this path.
:returns: ZnodeStat of the node if it exists, else None if the
node does not exist.
:rtype: :class:`~kazoo.protocol.states.ZnodeStat` or `None`.
:raises:
:exc:`~kazoo.exceptions.ZookeeperError` if the server
returns a non-zero error code.'

def exists(self, path, watch=None):

    return self.exists_async(path, watch).get()
