protected void addOverlayBlock(String name, String startAddress, long length)
			throws Exception {
		int transactionID = program.startTransaction("Add Overlay Block to test");
		Address address = program.getAddressFactory().getAddress(startAddress);
		Memory memory = program.getMemory();
		memory.createInitializedBlock(name, address, length, (byte) 0, TaskMonitor.DUMMY, true);
		program.endTransaction(transactionID, true);
	}
Tests for the symbol tree plugin.
Ghidra/Features/Base/src/test.slow/java/ghidra/app/plugin/core/symboltree/AbstractSymbolTreePluginExternalsTest.java