RRect inflate(double delta)

Returns a new RRect with edges and radii moved outwards by the given delta.

Source 

RRect inflate(double delta) {
  return new RRect.fromLTRBAndCorners(
    _value[0] - delta,
    _value[1] - delta,
    _value[2] + delta,
    _value[3] + delta,
    topLeft: new Radius.elliptical(
      _value[4] + delta,
      _value[5] + delta
    ),
    topRight: new Radius.elliptical(
      _value[6] + delta,
      _value[7] + delta
    ),
    bottomRight: new Radius.elliptical(
      _value[8] + delta,
      _value[9] + delta
    ),
    bottomLeft: new Radius.elliptical(
      _value[10] + delta,
      _value[11] + delta
    )
  );
}