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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def struct_time_to_jd(st):
 """ Return a float number representing the Julian Date for the given `struct_time`. NOTE: extra fields `tm_wday`, `tm_yday`, and `tm_isdst` are ignored. """

    year, month, day = st[:3]
    hours, minutes, seconds = st[3:6]

    # Convert time of day to fraction of day
    day += jdutil.hmsm_to_days(hours, minutes, seconds)

    return jdutil.date_to_jd(year, month, day)