AddWebOptimizer IWebHostEnvironment In ConfigureServices

[vindicatorr]

Why is one of the "optional" parameters for AddWebOptimizer asking for IWebHostEnvironment while in ConfigureServices when there is no IWebHostEnvironment parameter passed in at that time:

public static IServiceCollection AddWebOptimizer(this IServiceCollection services, IWebHostEnvironment env, CssBundlingSettings cssBundlingSettings, CodeBundlingSettings codeBundlingSettings, Action<IAssetPipeline> assetPipeline = null);