public void UnMerge(MSBuildPropertySet baseGrp, ISet<string> propsToExclude)
{
foreach (MSBuildProperty prop in baseGrp.Properties)
{
if (propsToExclude != null && propsToExclude.Contains(prop.Name))
continue;
MSBuildProperty thisProp = GetProperty(prop.Name);
if (thisProp != null && prop.Value.Equals(thisProp.Value, StringComparison.CurrentCultureIgnoreCase))
RemoveProperty(prop.Name);
}
}