def index(self, key, start=None, stop=None):
<EOL>temp, value = key<EOL>pos = self._list.index(temp, start, stop)<EOL>if value == self._dict[temp]:<EOL><INDENT>return pos<EOL><DEDENT>else:<EOL><INDENT>raise ValueError('<STR_LIT>'.format(key))<EOL><DEDENT>
Return the smallest *k* such that `itemssview[k] == key` and `start <= k
< end`.  Raises `KeyError` if *key* is not present.  *stop* defaults
to the end of the set.  *start* defaults to the beginning.  Negative
indexes are supported, as for slice indices.