NPE on Combo Box Item State Changed

[mglazer]

Here's a stack trace I get quite a bit with the latest version

ERROR [AWT-EventQueue-1] com.palantir.ptoss.cinch.swing.BoundSelection - could not invoke JComboBox binding
java.lang.NullPointerException
    at com.palantir.ptoss.cinch.swing.BoundSelection$Wiring$3.itemStateChanged(BoundSelection.java:190)
    at javax.swing.JComboBox.fireItemStateChanged(JComboBox.java:1205)
    at javax.swing.JComboBox.selectedItemChanged(JComboBox.java:1253)
    at javax.swing.JComboBox.contentsChanged(JComboBox.java:1309)
    at javax.swing.JComboBox.intervalRemoved(JComboBox.java:1331)
    at javax.swing.AbstractListModel.fireIntervalRemoved(AbstractListModel.java:161)
    at javax.swing.DefaultComboBoxModel.removeAllElements(DefaultComboBoxModel.java:169)
    at javax.swing.JComboBox.removeAllItems(JComboBox.java:751)

It occurs because I call remove on an empty combo box, and combo.getSelectedItem() returns null:

Object current = mutator.get();
Object newValue = combo.getSelectedItem();
if (newValue.equals(nullValue)) {

This should be changed to:

Objects.equals(newValue, nullValue)

Or something similar.

Really minor, but the error message clogs up my console.