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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 add_module(self, module):
 """ Ownership of module is transferred to the execution engine """

        if module in self._modules:
            raise KeyError("module already added to this engine")
        ffi.lib.LLVMPY_AddModule(self, module)
        module._owned = True
        self._modules.add(module)