code: def get_iam_policy(client=None, **kwargs):
      
      service_account=kwargs.pop('service_account')
      resp = client.projects().serviceAccounts().getIamPolicy(
          resource=service_account).execute()
      # TODO(supertom): err handling, check if 'bindings' is correct
      if 'bindings' in resp:
          return resp['bindings']
      else:
          return None
docs: service_account='string'