@staticmethod
def _generate_data(phg: str=None, rng: str=None, dfs: str=None, course: int
    =None, speed: int=None, altitude: int=None, comment: str=None) ->str:
    """
        Generate additional information for the information field.

        :param str phg: a PHG value
        :param str rng: an RNG value
        :param str dfs: a DFS value
        :param int course: course, in degrees
        :param int speed: speed, in knots
        :param int altitude: altitude, in feet
        :param str comment: a comment

        Position packets can have additional information in them, such as station power, antenna
        height, antenna gain, etc. These are described in APRS 1.01 C7. This will generate an
        information field based on these values.

        Note that PHG, RNG, DFS and course/speed are mutually exclusive. Altitude is specified as
        part of the comment and so can coexist with any of the other values.
        """
    data = ''
    if phg:
        data += phg
    elif rng:
        data += rng
    elif dfs:
        data += dfs
    elif course and speed:
        data += '{}/{}'.format(str(course).zfill(3), str(speed).zfill(3))
    if altitude:
        data += '/A={}'.format(str(altitude).zfill(6))
    if comment:
        data += comment
    return data
