/**
* Use the id for equals.
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (!(obj instanceof AbstractDrawing)) return false;
return id.equals(obj);
}
/**
* Use the id for hash code.
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return id.hashCode();
}