@Override
  public IFAState getState(int index) {
    return patternNodes[index];
  }
Given path pattern root.sg.*.s, the SimpleNFA is:

<p>initial -(root)-> state[0] -(sg)-> state[1] -(*)-> state[2] -(s)-> state[3] <br>
state[3] is final state

<p>Given path pattern root.**.s, the SimpleNFA is:

<p>initial -(root)-> state[0] -(*)-> state[1] -(s)-> state[2] <br>
with extra: state[1] -(*)-> state[1] and state[2] -(*)-> state[1] <br>
state[3] is final state

<p>Given path pattern root.sg.d with prefix match, the SimpleNFA is:

<p>initial -(root)-> state[0] -(sg)-> state[1] -(d)-> state[2] -(*)-> state[3] <br>
with extra: state[3] -(*)-> state[3] <br>
both state[2] and state[3] are final states
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/path/fa/nfa/SimpleNFA.java