@Test
	public void testGroupColoring_WithNoColorsInGroupedVertices_ChangeWhileGroupedChangesInternalVertices() {
		graphFunction("01002cf5");

		//
		// Group a node
		//
		FGVertex v1 = vertex("01002d06");
		FGVertex v2 = vertex("01002d0f");
		GroupedFunctionGraphVertex group = group("A", v1, v2);

		//
		// Change the group color
		//
		Color newGroupColor = Palette.CYAN;
		color(group, newGroupColor);

		//
		// Ungroup
		//
		ungroup(group);

		//
		// Test the grouped vertices colors
		//
		verifyColor(v1, newGroupColor);
		verifyColor(v2, newGroupColor);
	}
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