code: def parse_env_zones(self):
          '''returns a list of comma separated zones parsed from the GCE_ZONE environment variable.
          If provided, this will be used to filter the results of the grouped_instances call'''
          import csv
          reader = csv.reader([os.environ.get('GCE_ZONE',"")], skipinitialspace=True)
          zones = [r for r in reader]
          return [z for z in zones[0]f parse_env_zones(self):
          '''returns a list of comma separated zones parsed from the GCE_ZONE environment variable.
          If provided, this will be used to filter the results of the grouped_instances call'''
          import csv
          reader = csv.reader([os.environ.get('GCE_ZONE',"")], skipinitialspace=True)
          zones = [r for r in reader]
          return [z for z in zones[0]]
docs: returns a list of comma separated zones parsed from the GCE_ZONE environment variable.
          If provided, this will be used to filter the results of the grouped_instances call