if (spell1.Active.IsReady && mana >= spell1.Cost) { player.Cast(spell1); mana -= spell1.Cost; }In this example, the code will only cast the first spell if it is ready and the player has enough mana to cast it. This property is commonly used in game development, specifically in games where players have limited abilities and resources. It is likely that this property is included in a package library for game development in C#.