code: public void setRange(int indices[]) {
          this.currentVal = Arrays.toString(indices); 								// "[1,2,3]"
  		this.currentVal = this.currentVal.substring(1,this.currentVal.length()-1);	// "1,2,3"
      }
docs: /*
  This class will be like StringOption, but expect a string of numbers like Weka's Range
  e.g., 1,2,5-9,end will return something like [0,1,4,5,6,7,8,-1] which we will use later indicate e.g. multiple class attributes