code: def get_networks_count(context, filters=None):
      
      LOG.info("get_networks_count for tenant %s filters %s" %
               (context.tenant_id, filters))
      return db_api.network_count_all(context)
docs: Return the number of networks.
  
      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 RESOURCE_ATTRIBUTE_MAP object
          in neutron/api/v2/attributes.py.  Values in this dictiontary
          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.