'Get the version of the currently connected ZK server.
:returns: The server version, for example (3, 4, 3).
:rtype: tuple
.. versionadded:: 0.5'

def server_version(self):

    data = self.command('envi')
    string = ENVI_VERSION.match(data).group(1)
    return tuple([int(i) for i in string.split('.')])
