Lexeme removeTail(){
		Lexeme tail = this.pollLast();
		if(this.isEmpty()){
			this.pathBegin = -1;
			this.pathEnd = -1;
			this.payloadLength = 0;			
		}else{		
			this.payloadLength -= tail.getLength();
			Lexeme newTail = this.peekLast();
			this.pathEnd = newTail.getBegin() + newTail.getLength();
		}
		return tail;
	}
Lexeme removeTail(){
		Lexeme tail = this.pollLast();
		if(this.isEmpty()){
			this.pathBegin = -1;
			this.pathEnd = -1;
			this.payloadLength = 0;			
		}else{		
			this.payloadLength -= tail.getLength();
			Lexeme newTail = this.peekLast();
			this.pathEnd = newTail.getBegin() + newTail.getLength();
		}
		return tail;
	}
Lexeme removeTail ( ) { Lexeme tail = this . pollLast ( ) ; if ( this . isEmpty ( ) ) { this . pathBegin = - 1 ; this . pathEnd = - 1 ; this . payloadLength = 0 ; } else { this . payloadLength -= tail . getLength ( ) ; Lexeme newTail = this . peekLast ( ) ; this . pathEnd = newTail . getBegin ( ) + newTail . getLength ( ) ; } return tail ; }
移除尾部的Lexeme
@return
移除尾部的Lexeme