/// MovePicker class is used to pick one pseudo-legal move at a time from the
/// current position. The most important method is next_move(), which returns a
/// new pseudo-legal move each time it is called, until there are no moves left,
/// MovePicker class is used to pick one pseudo-legal move at a time from the
/// current position. The most important method is next_move(), which returns a
/// new pseudo-legal move each time it is called, until there are no moves left,