code: private void obtainIcon(@NonNull final TypedArray typedArray) {
          Drawable icon = typedArray.getDrawable(R.styleable.FloatingActionButton_android_icon);
          setIcon(icon);
      }
docs: Obtains the floating action button's icon from a specific typed array.
  
  @param typedArray
  The typed array, the ripple color should be obtained from, as an instance of the
  class {@link TypedArray}. The typed array may not be null