def __str__(self):
res = "<STR_LIT>"<EOL>for key in self._index:<EOL><INDENT>res += (str(key) + "<STR_LIT:\t>" + str(self._index[key]) + "<STR_LIT:\n>")<EOL><DEDENT>return res<EOL>
Produce a string representation of this index.

Use this with caution, as the full index is converted to string, which
might be quite large.