@Override
  public void setRadii(float[] radii) {
    if (radii == null) {
      Arrays.fill(mCornerRadii, 0);
      mRadiiNonZero = false;
    } else {
      Preconditions.checkArgument(radii.length == 8, "radii should have exactly 8 values");
      System.arraycopy(radii, 0, mCornerRadii, 0, 8);
      mRadiiNonZero = false;
      for (int i = 0; i < 8; i++) {
        mRadiiNonZero |= (radii[i] > 0);
      }
    }
    mIsPathDirty = true;
    invalidateSelf();
  }
Specify radii for each of the 4 corners. For each corner, the array contains 2 values,
[X_radius, Y_radius]. The corners are ordered top-left, top-right, bottom-right, bottom-left

@param radii the x and y radii of the corners
drawee/src/main/java/com/facebook/drawee/drawable/RoundedDrawable.java