@Test
	public void testDefaultSettingsOnCharArray() throws Exception {
		DataType charDT = dataMgr.resolve(new CharDataType(), null);
		SettingsDefinition[] settingsDefinitions = charDT.getSettingsDefinitions();

		assertTrue("Expect multiple settings on char type", settingsDefinitions.length > 2); // make sure we get more than two settings

		Array array = new ArrayDataType(charDT, 5, -1);
		assertArrayEquals(settingsDefinitions, array.getSettingsDefinitions());

		array = (Array) dataMgr.resolve(array, null);
		assertArrayEquals(settingsDefinitions, array.getSettingsDefinitions());

		Settings defaultSettings = array.getDefaultSettings();

		assertEquals(FormatSettingsDefinition.CHAR,
			FormatSettingsDefinition.DEF_CHAR.getChoice(defaultSettings));

		assertEquals(MutabilitySettingsDefinition.NORMAL,
			MutabilitySettingsDefinition.DEF.getChoice(defaultSettings));

		assertEquals(String.class, array.getValueClass(defaultSettings));

		FormatSettingsDefinition.DEF_CHAR.setChoice(defaultSettings, FormatSettingsDefinition.HEX);

		assertEquals(Array.class, array.getValueClass(defaultSettings));
	}
Test setting default and instance settings on Data.
Ghidra/Features/Base/src/test.slow/java/ghidra/program/database/data/SettingsTest.java