InitializeStaticAssetsResolver.cs

using Sitecore.Pipelines;
using Sitecore.StaticAssets.Infrastructure;

namespace Sitecore.StaticAssets.Pipelines
{
  public class InitializeStaticAssetsResolver  
  {
    private readonly string _assetPath;

    public InitializeStaticAssetsResolver(string assetPath)
    {
      _assetPath = assetPath;
    }

    public void Process(PipelineArgs args)
    {
      StaticAssets.Initialize(new StaticAssetResolver(Server.MapPath(_assetPath), HttpContext.Current.Cache));
    }
}