public static void ValidateProperty(this KeyValuePair <XName, InstanceValue> property, bool allowDelete)
{
if (property.Key == null)
{
throw Fx.Exception.AsError(new InvalidOperationException(SRCore.MetadataCannotContainNullKey));
}
if (property.Value == null)
{
throw Fx.Exception.AsError(new InvalidOperationException(SRCore.MetadataCannotContainNullValue(property.Key)));
}
if (!allowDelete && property.Value.IsDeletedValue)
{
throw Fx.Exception.AsError(new InvalidOperationException(SRCore.InitialMetadataCannotBeDeleted(property.Key)));
}
}