code: private void obtainThickness(@NonNull final TypedArray typedArray) {
          int defaultThickness = getContext().getResources()
                  .getDimensionPixelSize(R.dimen.circular_progress_bar_thickness_normal);
          thickness = typedArray
                  .getDimensionPixelSize(R.styleable.CircularProgressBar_android_thickness,
                          defaultThickness);
      }
docs: Obtains the progress bar's thickness from a specific typed array.
  
  @param typedArray
  The typed array, the thickness should be obtained from, as an instance of the class
  {@link TypedArray}. The typed array may not be null