@TargetApi(8)
  public String getExternalFilesDirectoryPath() {
    return this.context != null
            ? absPath(this.context.getExternalFilesDir(null))
            : "";
  }
@Test
  public void getExternalFilesDirectoryPathIsNotEmpty() {
    assertThat(contextUtil.getExternalFilesDirectoryPath(), endsWith("/external-files"));
  }