The example code in the javadoc for PseudoClass has a period/dot separating parameters rather than a comma in the call to pseudoClassStateChanged:

       @Override protected void invalidated() {
           pseudoClassStateChanged(MAGIC_PSEUDO_CLASS. get());
       }

instead of:

       @Override protected void invalidated() {
           pseudoClassStateChanged(MAGIC_PSEUDO_CLASS, get());
       }