@Test
	public void testRestoringWhenCodeBlocksHaveChanged_WillRegroup() {
		int transactionID = -1;
		try {
			transactionID = program.startTransaction(testName.getMethodName());
			doTestRestoringWhenCodeBlocksHaveChanged_WillRegroup();
		}
		finally {
			program.endTransaction(transactionID, false);
		}
	}
Tests that the app will recognize the case where the entry point to a function is invalid,
and generate the appropriate error message when trying to create a function graph.

Step 1: Make sure the function graph window is closed.
Step 2: Clear the entry point bytes
Step 3: Open the function graph window to generate the graph again.
Step 4: Check the error message.
Ghidra/Features/FunctionGraph/src/test.slow/java/ghidra/app/plugin/core/functiongraph/FunctionGraphGroupVertices1Test.java