def FormatRFC3339(datetime_instance: datetime.datetime) -> str:
  """Formats a datetime per RFC 3339.

  Args:
    datetime_instance: The datetime group to be formatted.

  Returns:
    str: A string formatted as per RFC3339 (e.g 2018-05-11T12:34:56.992Z)
  """
  return datetime_instance.isoformat('T') + 'Z'
Formats a datetime per RFC 3339.

Args:
datetime_instance: The datetime group to be formatted.

Returns:
str: A string formatted as per RFC3339 (e.g 2018-05-11T12:34:56.992Z)
libcloudforensics/providers/gcp/internal/common.py