docs: async def list_instances(self,
                               project,
                               page_size=100,
                               instance_filter=None):
          """Fetch all instances in a GCE project.
  
          You can find the endpoint documentation `here <https://cloud.
          google.com/compute/docs/reference/latest/instances/
          aggregatedList>`__.
  
          Args:
              project (str): unique, user-provided project ID.
              page_size (int): hint for the client to only retrieve up to
                  this number of results per API call.
              instance_filter (str): endpoint-specific filter string used
                  to retrieve a subset of instances. This is passed
                  directly to the endpoint's "filter" URL query parameter.
          Returns:
              list(dicts): data of all instances in the given
                  :obj:`project`
          """
          url = (f'{self.BASE_URL}{self.api_version}/projects/{project}'
                 '/aggregated/instances')
          params = {'maxResults': page_size}
          if instance_filter:
              params['filter'] = instance_filter
  
          responses = await self.list_all(url, params)
          instances = self._parse_rsps_for_instances(responses)
          return instances