/// <summary>
/// Check which of the supplied plots are available for user
/// </summary>
/// <param name="plots">The plots to check</param>
/// <returns>The available plots</returns>
public IEnumerable <Plot> GetAvailablePlots(IEnumerable <Plot> plots)
{
return(plots.Where(p => Buildings.All(b => b.PlotId != p.Id)));
}