/// <devdoc>
/// Combines region1 & region2 into this region. The regions cannot be null.
/// The three regions need not be distinct. For example, the sourceRgn1 can equal this region.
/// </devdoc>
public IntNativeMethods.RegionFlags CombineRegion(WindowsRegion region1, WindowsRegion region2, RegionCombineMode mode)
{
return(IntUnsafeNativeMethods.CombineRgn(new HandleRef(this, this.HRegion), new HandleRef(region1, region1.HRegion), new HandleRef(region2, region2.HRegion), mode));
}