def hash_lookup(self, hashsum):
return self.memo_lookup_table[hashsum]<EOL>
Lookup a hash in the memoization table.

        Will raise a KeyError if hash is not in the memoization lookup table.

        Args:
            - hashsum (str?): The same hashes used to uniquely identify apps+inputs

        Returns:
            - Lookup result, this is unlikely to be None, since the hashes are set by this
              library and could not miss entried in it's dict.

        Raises:
            - KeyError: if hash not in table