code: public final void setBackground(@DrawableRes final int resourceId) {
          this.background = ContextCompat.getDrawable(getContext(), resourceId);
          this.backgroundBitmap = null;
          this.backgroundId = -1;
          this.backgroundColor = -1;
          adaptBackground();
      }
docs: Sets the background of the bottom sheet.
  
  @param resourceId
  The resource id of the background, which should be set, as an {@link Integer} value.
  The resource id must correspond to a valid drawable resource