code: private void removeTransitionPathRegisterEntries(String str)
      {
          MDAGNode currentNode = sourceNode;
  
          int charCount = str.length();
  
          for (int i = 0; i < charCount; i++)
          {
              currentNode = currentNode.transition(str.charAt(i));
              if (equivalenceClassMDAGNodeHashMap.get(currentNode) == currentNode)
                  equivalenceClassMDAGNodeHashMap.remove(currentNode);
  
              //The hashCode of an MDAGNode is cached the first time a hash is performed without a cache value present.
              //Since we just hashed currentNode, we must clear this regardless of its presence in equivalenceClassMDAGNodeHashMap
              //since we're not actually declaring equivalence class representatives here.
              if (currentNode != null) currentNode.clearStoredHashCode();
          }
      }
docs: 从登记簿中移除路径对应的状态们<br>
  Removes from equivalenceClassMDAGNodeHashmap the entries of all the nodes in a _transition path.
  
  @param str a String corresponding to a _transition path from sourceNode