UnityEditor.TerrainDetailContextMenus.AddDetailTexture C# (CSharp) Method

        internal static void AddDetailTexture(MenuCommand item)
        {
            DetailTextureWizard wizard = TerrainWizard.DisplayTerrainWizard<DetailTextureWizard>("Add Grass Texture", "Add");
            wizard.m_DetailTexture = null;
            wizard.InitializeDefaults((Terrain) item.context, -1);
        }