'Return the number of ports.
The result depends on the identity of the user making the request
(as indicated by the context) as well as any filters.
:param context: neutron api request context
:param filters: a dictionary with keys that are valid keys for
a network as listed in the
:obj:`RESOURCE_ATTRIBUTE_MAP` object in
:file:`neutron/api/v2/attributes.py`.  Values in this
dictionary are an iterable containing values that will
be used for an exact match comparison for that value.
Each result returned by this function will have matched
one of the values for each key in filters.
.. note:: this method is optional, as it was not part of the originally
defined plugin API.'

def get_ports_count(self, context, filters=None):

    raise NotImplementedError()
