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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 lcase(instr, lenout=_default_len_out):
 """ Convert the characters in a string to lowercase. http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/lcase_c.html :param instr: Input string. :type instr: str :param lenout: Maximum length of output string. :type lenout: int :return: Output string, all lowercase. :rtype: str """

    instr = stypes.stringToCharP(instr)
    lenout = ctypes.c_int(lenout)
    outstr = stypes.stringToCharP(lenout)
    libspice.lcase_c(instr, lenout, outstr)
    return stypes.toPythonString(outstr)