ConcatToken(Token t1,
    Token t2) 
{
        
            super(Token.CONCAT);
            this.child = t1;
            this.child2 = t2;
}

 Token getChild(int index) 
{
            return index == 0 ? this.child : this.child2;
}

 int size() 
{
            return 2;
}

 public String toString(int options) 
{
            String ret;
            if (this.child2.type == CLOSURE && this.child2.getChild(0) == this.child) {
                ret = this.child.toString(options)+"+";
            } else if (this.child2.type == NONGREEDYCLOSURE && this.child2.getChild(0) == this.child) {
                ret = this.child.toString(options)+"+?";
            } else
                ret = this.child.toString(options)+this.child2.toString(options);
            return ret;
}