'Declares the MTypes the client wishes to subscribe to, implicitly
defined with the MType binding methods
:meth:`~astropy.samp.client.SAMPClient.bind_receive_notification`
and :meth:`~astropy.samp.client.SAMPClient.bind_receive_call`.
An optional ``subscriptions`` map can be added to the final map passed
to the :meth:`~astropy.samp.hub_proxy.SAMPHubProxy.declare_subscriptions`
method.
Parameters
subscriptions : dict, optional
Dictionary containing the list of MTypes to subscribe to, with the
same format of the ``subscriptions`` map passed to the
:meth:`~astropy.samp.hub_proxy.SAMPHubProxy.declare_subscriptions`
method.'

def declare_subscriptions(self, subscriptions=None):

    if self._callable:
        self._declare_subscriptions(subscriptions)
    else:
        raise SAMPClientError(u'Client    not    callable.')
