private void OnBuildBegin(vsBuildScope Scope, vsBuildAction Action)
        {
            var projects = (object[]) applicationObject.ActiveSolutionProjects;
            foreach (Project project in projects)
            {
                IterateProjectFiles((ProjectItems)project.ProjectItems);
            }
        }

        private void IterateProjectFiles(ProjectItems items)
        {
            foreach (ProjectItem file in items)
            {
                if (file.Object != null && file.Object is VSProjectItem)
                {
                    var projectItem = (VSProjectItem)file.Object;
                    if (projectItem.ProjectItem.Name.EndsWith(".blml"))
                    {
                        projectItem.RunCustomTool();
                    }
                }
            }
        }