@Override
                  public CharSequence getCharContent(boolean ignoreEncodingErrors)
                      throws IOException {
                    return "class Test {}";
                  }
Run {@link TestProcessor} in a compilation with the given {@code options}, and prevent the
compilation from accessing classes with the qualified names in {@code maskFromClasspath}.
common/src/test/java/com/google/auto/common/GeneratedAnnotationsTest.java