public FileInputStream openInputStream(File file) {
    try {
      return openInputStreamOrThrowIOE(file);
    } catch (IOException e) {
      throw new IllegalStateException("Can not open file " + file, e);
    }
  }
@Test
  public void openInputStream_opens_existing_file() throws Exception {
    File file = temp.newFile();
    FileUtils.write(file, "foo");

    try (FileInputStream input = underTest.openInputStream(file)) {
      assertThat(IOUtils.toString(input)).isEqualTo("foo");
    }
  }