private boolean isModifiersOnly(KeyEvent event) {
			String keyText = KeyEvent.getKeyText(event.getKeyCode());
			return keyText.equals(KeyEvent.getKeyText(KeyEvent.VK_CONTROL)) ||
				keyText.equals(KeyEvent.getKeyText(KeyEvent.VK_ALT)) ||
				keyText.equals(KeyEvent.getKeyText(KeyEvent.VK_SHIFT)) ||
				keyText.equals(KeyEvent.getKeyText(KeyEvent.VK_META));
		}
Clears the state of this class and notifies this client.  This effectively allows for the
programmatic setting of the keystroke in use to be null, or in the 'no keystroke set' state.
Ghidra/Framework/Docking/src/main/java/docking/KeyEntryTextField.java