'" Get the index of the string in the Shared String table.'

def _get_shared_string_index(self, string):

    if (string not in self.string_table):
        index = self.unique_count
        self.string_table[string] = index
        self.count += 1
        self.unique_count += 1
        return index
    else:
        index = self.string_table[string]
        self.count += 1
        return index
