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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 extern_call(self, context_handle, func, args_ptr, args_len):
 """Given a callable, call it."""

    c = self._ffi.from_handle(context_handle)
    runnable = c.from_value(func[0])
    args = tuple(c.from_value(arg[0]) for arg in self._ffi.unpack(args_ptr, args_len))
    return self.call(c, runnable, args)