totalShift property
      
      Offset
      get
      totalShift
      
    
    
all BoxConstraints in constraints would be calculated according to the size
Implementation
Offset get totalShift {
  final shift = switch (axis) {
    Axis.horizontal => Offset(size.width, 0),
    Axis.vertical => Offset(0, size.height),
  };
  return shift;
}