@Test
public void testRemovable() throws Exception {

  String program = "void notCalled() { }"
      + "void main() { }";
  TranslationUnit tu = ParseHelper.parse(program);
  assertEquals(1, FunctionReductionOpportunities.findOpportunities(
      MakeShaderJobFromFragmentShader.make(tu),
        new ReducerContext(false, ShadingLanguageVersion.ESSL_100,
            new RandomWrapper(0), new IdGenerator())).size());
}