@Test
  public void annotationsToApplyRepeated() {
    JavaFileObject file = JavaFileObjects.forResource("bad/AnnotationsToApplyRepeated.java");
    Compilation compilation = javac.compile(file);
    assertThat(compilation).failed();
    assertThat(compilation).hadErrorContaining("More than one @java.lang.SuppressWarnings");
  }
We also don't allow you to have the same annotation appear more than once inside a given
{@code @AnnotationsToApply}, even with the same values.
factory/src/test/java/com/google/auto/factory/processor/AutoFactoryProcessorNegativeTest.java