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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 copy(self, from_path, to_hdfs, to_path):
 """ Copy file from one filesystem to another. :type from_path: str :param from_path: the path of the source file :type to_hdfs: :class:`hdfs` :param to_hdfs: destination filesystem :type to_path: str :param to_path: the path of the destination file :raises: :exc:`~exceptions.IOError` """

        _complain_ifclosed(self.closed)
        if isinstance(to_hdfs, self.__class__):
            to_hdfs = to_hdfs.fs
        return self.fs.copy(from_path, to_hdfs, to_path)