@Override
  public boolean equals(final Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;
    PropertyReferenceBase other = (PropertyReferenceBase)o;

    return getElement() == other.getElement() && getKeyText().equals(other.getKeyText());
  }
@Override
  public boolean equals(final Object o)