static void DefaultOnGUI_UnitToolbar(
     Object asset,
     ShaderBuildReport r,
     ShaderBuildReport.GPUProgram po,
     ShaderBuildReport.CompileUnit cu,
     ShaderBuildReport.PerformanceUnit pu,
     ShaderBuildReport.ProgramPerformanceMetrics p,
     ShaderBuildReport reference,
     string assetGUID)
 {
 }
 static void DefaultOnGUI_ProgramToolbar(
     Object asset,
     ShaderBuildReport report,
     ShaderBuildReport.GPUProgram program,
     ShaderBuildReport reference,
     string assetGUID)
 {
     if (!string.IsNullOrEmpty(program.sourceCode) && GUILayout.Button("Open", EditorStyles.toolbarButton))
     {
         program.OpenSourceCode();
     }
 }