human
Solve the following python programming problem given the following code:
def _make_is_append_mode() : 
    from ctypes import cdll, c_size_t, c_void_p, c_int, c_char, Structure, POINTER, cast 
    from ctypes.util import find_msvcrt 
    def _dummy_is_append_mode(fd) : 
        warnings.warn ('Could not find appropriate MS Visual C Runtime library or library is corrupt/misconfigured.
cannot determine whether your file object was opened in append mode.  Please consider using a file object opened in write mode instead.') 
        return False 
msvcrt_dll = find_msvcrt () 
    if (msvcrt_dll is None) : 
        return <MASK> 
msvcrt = cdll.LoadLibrary (msvcrt_dll) 
    IOINFO_L2E = 5 
    IOINFO_ARRAY_ELTS = (1 << IOINFO_L2E) 
    IOINFO_ARRAYS = 64 
    FAPPEND = 32 
    _NO_CONSOLE_FILENO = (- 2) 
    intptr_t = POINTER (c_int) 
    class my_ioinfo (Structure) : 
        _fields_ = [('osfhnd', intptr_t), ('osfile', c_char)] 
_msize = msvcrt._msize 
    _msize.argtypes = (c_void_p,) 
    _msize.restype = c_size_t 
    __pioinfo = cast (msvcrt.__pioinfo, POINTER (POINTER (c_char))) 
    global _sizeof_ioinfo 
    if (__pioinfo [0] is not None) : 
        _sizeof_ioinfo = (_msize (__pioinfo [0]) // IOINFO_ARRAY_ELTS) 
if (not _sizeof_ioinfo) : 
        return _dummy_is_append_mode 
def _is_append_mode(fd) : 
        global _sizeof_ioinfo 
        if (fd != _NO_CONSOLE_FILENO) : 
            idx1 = (fd >> IOINFO_L2E) 
            idx2 = (fd & ((1 << IOINFO_L2E) - 1)) 
            if ((0 <= idx1 < IOINFO_ARRAYS) and (__pioinfo [idx1] is not None)) : 
                pio = c_void_p ((cast (__pioinfo [idx1], c_void_p).value + (idx2 * _sizeof_ioinfo))) 
                ioinfo = cast (pio, POINTER (my_ioinfo)).contents 
                return bool ((ord (ioinfo.osfile) & FAPPEND)) 
return False 
return _is_append_mode 
    
    Given the code above, what is a proper replacement for <MASK>?
assistant
#Here is Python code to find appropriate MS Visual C Runtime library or library is corrupt/misconfigured.
_dummy_is_append_mode