docs: protected synchronized void removeShapeGeometryChangeListener(ShapeGeometryChangeListener listener) {
  		assert listener != null : AssertMessages.notNullParameter();
  		if (this.geometryListeners != null) {
  			this.geometryListeners.remove(listener);
  			if (this.geometryListeners.isEmpty()) {
  				this.geometryListeners = null;
  			}
  		}
  	}