docs: public String getTypes()    {
  		StringBuffer sb = new StringBuffer();
  		String ste;
  		String[] str;
  		for (int i = 0; i < leftChilds.size(); i++) {
  			sb.append(leftChilds.get(i).getTypes());
  		}
  		if(relation!=null)
  			sb.append(relation);	
  		else
  			sb.append("核心词");
  		sb.append(" ");
  		for (int i = 0; i < rightChilds.size(); i++) {
  			sb.append(rightChilds.get(i).getTypes());
  		}
  				
  			return sb.toString();	
  	}