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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 as_bitcode(self):
 """ Return the module's LLVM bitcode, as a bytes object. """

        ptr = c_char_p(None)
        size = c_size_t(-1)
        ffi.lib.LLVMPY_WriteBitcodeToString(self, byref(ptr), byref(size))
        if not ptr:
            raise MemoryError
        try:
            assert size.value >= 0
            return string_at(ptr, size.value)
        finally:
            ffi.lib.LLVMPY_DisposeString(ptr)