code: public void setPadding(int left, int top, int right, int bottom) {
          final LayerState layerState = mLayerState;
          layerState.mPaddingLeft = left;
          layerState.mPaddingTop = top;
          layerState.mPaddingRight = right;
          layerState.mPaddingBottom = bottom;
  
          // Clear relative padding values.
          layerState.mPaddingStart = -1;
          layerState.mPaddingEnd = -1;
      }
docs: Sets the absolute padding.
  <p/>
  If padding in a dimension is specified as {@code -1}, the resolved padding will use the value
  computed according to the padding mode (see {@link #setPaddingMode(int)}).
  <p/>
  Calling this method clears any relative padding values previously set using {@link
  #setPaddingRelative(int, int, int, int)}.
  
  @param left   the left padding in pixels, or -1 to use computed padding
  @param top    the top padding in pixels, or -1 to use computed padding
  @param right  the right padding in pixels, or -1 to use computed padding
  @param bottom the bottom padding in pixels, or -1 to use computed padding
  @attr ref android.R.styleable#LayerDrawable_paddingLeft
  @attr ref android.R.styleable#LayerDrawable_paddingTop
  @attr ref android.R.styleable#LayerDrawable_paddingRight
  @attr ref android.R.styleable#LayerDrawable_paddingBottom
  @see #setPaddingRelative(int, int, int, int)