@Nullable
    State findNextState(char code) {
        State nextState = success.get(code);
        if (nextState == null && depth == 0) {
            return this;
        }
        return nextState;
    }
points to the index of {@link AhoCorasickDoubleArrayTrie#words}
turms-plugins/turms-plugin-antispam/src/main/java/im/turms/plugin/antispam/core/ac/State.java