code: def get_project_collection(self, collection_id):
          
          route_values = {}
          if collection_id is not None:
              route_values['collectionId'] = self._serialize.url('collection_id', collection_id, 'str')
          response = self._send(http_method='GET',
                                location_id='8031090f-ef1d-4af6-85fc-698cd75d42bf',
                                version='5.1-preview.2',
                                route_values=route_values)
          return self._deserialize('TeamProjectCollection', response)
docs: GetProjectCollection.
          [Preview API] Get project collection with the specified id or name.
          :param str collection_id:
          :rtype: :class:`<TeamProjectCollection> <azure.devops.v5_1.core.models.TeamProjectCollection>`