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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 cio_open(cinfo, src=None):
 """Wrapper for openjpeg library function opj_cio_open."""

    argtypes = [ctypes.POINTER(CommonStructType), ctypes.c_char_p,
                ctypes.c_int]
    OPENJPEG.opj_cio_open.argtypes = argtypes
    OPENJPEG.opj_cio_open.restype = ctypes.POINTER(CioType)

    if src is None:
        length = 0
    else:
        length = len(src)

    cio = OPENJPEG.opj_cio_open(ctypes.cast(cinfo,
                                            ctypes.POINTER(CommonStructType)),
                                src,
                                length)
    return cio