code: @TargetApi(Build.VERSION_CODES.FROYO)
      @Nullable
      public static CharSequence[] optCharSequenceArray(@Nullable Bundle bundle, @Nullable String key) {
          return optCharSequenceArray(bundle, key, new CharSequence[0]);
      }
docs: Returns a optional {@link CharSequence} array value. In other words, returns the value mapped by key if it exists and is a {@link CharSequence} array.
  The bundle argument is allowed to be {@code null}. If the bundle is null, this method returns null.
  @param bundle a bundle. If the bundle is null, this method will return null.
  @param key a key for the value.
  @return a {@link CharSequence} array value if exists, null otherwise.
  @see android.os.Bundle#getCharSequenceArray(String)