Labeled.labelPadding StyleableProperty NPE when setting to default value.

I am setting the Labeled.labelPadding to its default value doing:
Object val = styleable.getInitialValue() == null ? null : styleable.getInitialValue().convert(null);
labeled.impl_cssSet(styleable, val);

I am getting an NPE. I can't reset this property to its initial value. Any styling removed from the SceneBuilder, will be node reflected.


WARNING: javafx.scene.Node impl_cssSet Failed to set css [StyleableProperty {owningClass: javafx.scene.control.Labeled, fieldName: labelPadding, property: -fx-label-padding, converter: InsetsConverter, initialValue: '', inherits: false, subProperties: []}]

java.lang.NullPointerException: cannot set labelPadding to null
at javafx.scene.control.Labeled$8.invalidated(Labeled.java:371)
testCheckResetProperties Button start
testCheckResetProperties Check Box start
at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:88)
at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:122)
at javafx.scene.control.Labeled.setLabelPadding(Labeled.java:393)
at javafx.scene.control.Labeled.impl_cssSet(Labeled.java:597)
at javafx.scene.Node.impl_cssSet(Node.java:6347)