'Get a Server or None.
Returns the current version of the server immediately, even if it\'s
Unknown or absent from the topology. Only use this in unittests.
In driver code, use select_server_by_address, since then you\'re
assured a recent view of the server\'s type and wire protocol version.'

def get_server_by_address(self, address):

    return self._servers.get(address)
