public XamlWriterInternalBase (XamlSchemaContext schemaContext, XamlWriterStateManager manager)
{
this.sctx = schemaContext;
this.manager = manager;
var p = new PrefixLookup (sctx) { IsCollectingNamespaces = true }; // it does not raise unknown namespace error.
service_provider = new ValueSerializerContext (p, schemaContext);
}