ModifierNodeInspectableProperties
Reports a modifier element that describes itself to nothing: one implementing SwingModifier.InspectableElement that overrides neither name nor declaredValues.
Both members carry a default, so such an element compiles and a tool showing the modifier a component carries reads the class name off it and no declared values at all. Overriding one of them says what the entry is called, or what it declares, in the one place a tool can read it.
An element carrying no state a reader declared is passed over: its class name is the whole of what it is, and it has no values to name. So is an interface or an abstract class - neither is an entry on a modifier, and the classes below it declare their own.
Only direct supertypes qualified by the library SwingModifier or its import alias are matched. This avoids treating an unrelated type with the same simple name as this library's element contract.