code: public void addReadFields2(FieldSet readFields) {
  		if(this.readFields2 == null) {
  			this.readFields2 = new FieldSet(readFields);
  		} else {
  			this.readFields2.addAll(readFields);
  		}
  	}
docs: Adds, to the existing information, field(s) that are read in
  the source record(s) from the second input.
  
  @param readFields the position(s) in the source record(s)