Convert a microsecond-precision timestamp to datetime.

    Args:
        value (str): The RFC3339 string to convert.

    Returns:
        datetime.datetime: The datetime object equivalent to the timestamp in
            UTC.

def from_rfc3339(value):
    """Convert a microsecond-precision timestamp to datetime.

    Args:
        value (str): The RFC3339 string to convert.

    Returns:
        datetime.datetime: The datetime object equivalent to the timestamp in
            UTC.
    """
    return datetime.datetime.strptime(value, _RFC3339_MICROS).replace(tzinfo=pytz.utc)