public final class NoClass extends java.lang.ObjectMarker class used with annotations to indicate "no class". This is a silly but necessary work-around -- annotations cannot take nulls as either default or explicit values. Hence for class values we must explicitly use a bogus placeholder to denote equivalent of "no class" (for which 'null' is usually the natural choice).
Note that since 2.4, most (but not all!
JsonTypeInfo.defaultImpl()is a notable exception}) usage should start using
Voidinstead as the "not defined" marker.