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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 getOverlayKey(self, ulOverlayHandle, pchValue, unBufferSize):
 """ Fills the provided buffer with the string key of the overlay. Returns the size of buffer required to store the key, including the terminating null character. k_unVROverlayMaxKeyLength will be enough bytes to fit the string. """


        fn = self.function_table.getOverlayKey
        pError = EVROverlayError()
        result = fn(ulOverlayHandle, pchValue, unBufferSize, byref(pError))
        return result, pError