def METHOD_NAME(self) -> None:
    """Closes access to the shared memory from this instance but does
    not destroy the shared memory block."""
    if self._mmap is not None:
        try:
            self._mmap.METHOD_NAME()
        except BufferError:
            if not self.ignore_close_failure:
                raise
        self._mmap = None
    if self._fd >= 0:
        os.METHOD_NAME(self._fd)
        self._fd = -1