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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 gfsntc(target, fixref, method, abcorr, obsrvr, dref, dvec, crdsys, coord, relate, refval, adjust, step, nintvals, cnfine, result=None):
 """ Determine time intervals for which a coordinate of an surface intercept position vector satisfies a numerical constraint. http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/gfsntc_c.html :param target: Name of the target body. :type target: str :param fixref: Body fixed frame associated with the target. :type fixref: str :param method: Name of method type for surface intercept calculation. :type method: str :param abcorr: Aberration correction flag :type abcorr: str :param obsrvr: Name of the observing body. :type obsrvr: str :param dref: Reference frame of direction vector of dvec. :type dref: str :param dvec: Pointing direction vector from the observer. :type dvec: 3-Element Array of floats :param crdsys: Name of the coordinate system containing COORD. :type crdsys: str :param coord: Name of the coordinate of interest :type coord: str :param relate: Relational operator. :type relate: str :param refval: Reference value. :type refval: float :param adjust: Absolute extremum adjustment value. :type adjust: float :param step: Step size in seconds for finding angular separation events. :type step: float :param nintvals: Workspace window interval count. :type nintvals: int :param cnfine: SPICE window to which the search is restricted. :type cnfine: spiceypy.utils.support_types.SpiceCell :param result: Optional SPICE window containing results. :type result: spiceypy.utils.support_types.SpiceCell """

    assert isinstance(cnfine, stypes.SpiceCell)
    assert cnfine.is_double()
    if result is None:
        result = stypes.SPICEDOUBLE_CELL(2000)
    else:
        assert isinstance(result, stypes.SpiceCell)
        assert result.is_double()
    target = stypes.stringToCharP(target)
    fixref = stypes.stringToCharP(fixref)
    method = stypes.stringToCharP(method)
    abcorr = stypes.stringToCharP(abcorr)
    obsrvr = stypes.stringToCharP(obsrvr)
    dref = stypes.stringToCharP(dref)
    dvec = stypes.toDoubleVector(dvec)
    crdsys = stypes.stringToCharP(crdsys)
    coord = stypes.stringToCharP(coord)
    relate = stypes.stringToCharP(relate)
    refval = ctypes.c_double(refval)
    adjust = ctypes.c_double(adjust)
    step = ctypes.c_double(step)
    nintvals = ctypes.c_int(nintvals)
    libspice.gfsntc_c(target, fixref, method, abcorr, obsrvr,
                      dref, dvec, crdsys, coord, relate, refval,
                      adjust, step, nintvals, ctypes.byref(cnfine),
                      ctypes.byref(result))
    return result