code: package it.unibz.inf.vig_mappings_analyzer.datatypes;
  
  //import java.util.Collections;
  import java.util.HashSet;
  import java.util.Set;
  
  public class Argument{
      private Set<Field> fillingFields;
  
      public Argument(){
  	this.fillingFields = new HashSet<Field>();
      }
  
      public void addFillingField(Field field){
  	this.fillingFields.add(field);
      }
  
      public Set<Field> getFillingFields(){
  	// return Collections.unmodifiableSet(fillingFields);
  	return fillingFields;
      }
  
      /**
       * It returns true if this.fillingFields.equals(other.fillingFields)
       * @param other
       * @return
       */
      public boolean hasSameFillingFields(Argument other){
  	boolean result = this.fillingFields.equals(other.fillingFields);
  	return result;
      }
  
      @Override
      public String toString() {
  	return fillingFields.toString();
      }
  };
  