public void ResizePicture(PictureId pictureId, PictureSize newSize)
{
var picture = FindPicture(pictureId);
if (picture == null)
{
throw new InvalidOperationException("Cannot resize a picture that I dont't have");
}
picture.Resize(newSize);
}
private Picture FindPicture(PictureId id)
{
return(Pictures.FirstOrDefault(t => t.Id == id));
}