private static void VerifyEmittedHandle <TEntity, THandle>(DefinitionMetadata <TEntity, THandle> metadata,
                                                            THandle handle)
 {
     if (!metadata.Handle.Equals(handle))
     {
         throw new InvalidOperationException("Reserved and emitted metadata handles are different.");
     }
 }
 private static void EnsureMetadataWasNotEmitted <TEntity, THandle>(DefinitionMetadata <TEntity, THandle> metadata,
                                                                    TEntity entity)
 {
     if (metadata.IsEmitted)
     {
         var friendlyName = MetadataHelper.GetFriendlyName(entity);
         throw new InvalidOperationException($"Entity metadata was already emitted before: {friendlyName}");
     }
 }