code: public @ColorInt
      Integer getHighlightColor(@NonNull View view, @NonNull String attribute) {
          try {
              return attributeColors.get(new Pair<>(view.getId(), attribute));
          } catch (NullPointerException e) {
              return 0;
          }
      }
docs: Gets the highlighting color for a given view/attribute pair.
  
  @param view      the view using this attribute.
  @param attribute the attribute's name.
  @return the {@link ColorInt} associated with this view/attribute pair, or 0 if there is none.