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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 external_answer(self, *sequences):
 """Try to get answer from known external libraries. """

        # if this feature disabled
        if not getattr(self, 'external', False):
            return
        # all external libs doesn't support test_func
        if hasattr(self, 'test_func') and self.test_func is not self._ident:
            return
        # try to get external libs for algorithm
        libs = libraries.get_libs(self.__class__.__name__)
        for lib in libs:
            # if conditions not satisfied
            if not lib.check_conditions(self, *sequences):
                continue
            # if library is not installed yet
            if not lib.get_function():
                continue

            prepared_sequences = lib.prepare(*sequences)
            # fail side libraries silently and try next libs
            try:
                return lib.func(*prepared_sequences)
            except Exception:
                pass