discardableContent method
Determines if this artifact contains content that can be discarded.
An artifact is considered discardable if it is very small
(area ≤ _maxDiscardableArea)
or if it is classified as a line.
Returns true if the artifact can be discarded, false otherwise.
Implementation
bool discardableContent() {
return area <= _maxDiscardableArea || isConsideredLine();
}