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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 insrtc(item, inset):
 """ Insert an item into a character set. http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/insrtc_c.html :param item: Item to be inserted. :type item: str or list of str :param inset: Insertion set. :type inset: spiceypy.utils.support_types.SpiceCell """

    assert isinstance(inset, stypes.SpiceCell)
    if isinstance(item, list):
        for c in item:
            libspice.insrtc_c(stypes.stringToCharP(c), ctypes.byref(inset))
    else:
        item = stypes.stringToCharP(item)
        libspice.insrtc_c(item, ctypes.byref(inset))