internal void DisableShadow(IntPtr handle)
        {
            var cs = NATIVE.GetClassLong(handle, NATIVE.GCL_STYLE);

            if ((cs & NATIVE.CS_DROPSHADOW) == NATIVE.CS_DROPSHADOW)
            {
                cs = cs & ~NATIVE.CS_DROPSHADOW;
                NATIVE.SetClassLong(handle, NATIVE.GCL_STYLE, cs);
            }
        }