private String system;
	
  @Override
  public String getSystem() {
    return system;
  }

  @Override
  public boolean hasSystem() {
    return system != null;
  }
  
  public CodeType setSystem(String system) {
    this.system = system;
    return this;
  }

  @Override
  public String getVersion() {
    return null;
  }

  @Override
  public boolean hasVersion() {
    return false;
  }
  
  @Override
  public String getDisplay() {
    return null;
  }

  @Override
  public boolean hasDisplay() {
    return false;
  }