docs: function(i, query) {
        if(this.COMPARISON_OPERATORS.indexOf(query.substr(i,3)) >= 0)  return [i+3, new this(query.substr(i,3))];
        else if(this.COMPARISON_OPERATORS.indexOf(query.substr(i,2)) >= 0) return [i+2, new this(query.substr(i,2))];
        else if(this.COMPARISON_OPERATORS.indexOf(query.substr(i,1)) >= 0) return [i+1, new this(query.substr(i,1))];
        else return null;
      }