public TextLayoutBuilder setShadowLayer(float radius, float dx, float dy, @ColorInt int color) {
    mParams.createNewPaintIfNeeded();
    mParams.mShadowRadius = radius;
    mParams.mShadowDx = dx;
    mParams.mShadowDy = dy;
    mParams.mShadowColor = color;
    mParams.paint.setShadowLayer(radius, dx, dy, color);
    mSavedLayout = null;
    return this;
  }
Sets the shadow layer for the layout.

@param radius The radius of the blur for shadow
@param dx The horizontal translation of the origin
@param dy The vertical translation of the origin
@param color The shadow color
@return This {@link TextLayoutBuilder} instance
library/src/main/java/com/facebook/fbui/textlayoutbuilder/TextLayoutBuilder.java