((Line)obj1).removePropertyChangeListener(Line.PROP_LENGTH, newLine);
newLine.removePropertyChangeListener(Line.PROP_LENGTH, (Line)obj1);
}
else {
((Circle)obj1).removePropertyChangeListener(Circle.PROP_RADIUS, newLine);
newLine.removePropertyChangeListener(Circle.PROP_RADIUS, (Circle)obj1);
}
if (!(obj2 instanceof Double)) {
((Line)obj2).removePropertyChangeListener(Line.PROP_ANGLE, newLine);
newLine.removePropertyChangeListener(Line.PROP_ANGLE, (Line)obj2);
}