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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 _fdopen_ver2(self, file_des, mode='r', bufsize=None):
 # pylint: disable=unused-argument """Returns an open file object connected to the file descriptor file_des. Args: file_des: An integer file descriptor for the file object requested. mode: Additional file flags. Currently checks to see if the mode matches the mode of the requested file object. bufsize: ignored. (Used for signature compliance with __builtin__.fdopen) Returns: File object corresponding to file_des. Raises: OSError: if bad file descriptor or incompatible mode is given. TypeError: if file descriptor is not an integer. """

        if not is_int_type(file_des):
            raise TypeError('an integer is required')

        try:
            return FakeFileOpen(self.filesystem).call(file_des, mode=mode)
        except IOError as exc:
            self.filesystem.raise_os_error(exc.errno, exc.filename)