Get a file from the filesystem. Returns a SimFile or None.

def get(self, path):
        """
        Get a file from the filesystem. Returns a SimFile or None.
        """
        mountpoint, chunks = self.get_mountpoint(path)

        if mountpoint is None:
            return self._files.get(self._join_chunks(chunks))
        else:
            return mountpoint.get(chunks)