private static void Visit(EntityElementBuilder entityConfig, Action <EntityElementBuilder> visitor)
 {
     foreach (var relation in entityConfig.RelationConfigs.Where(x => x.TargetEntityElementConfig != null))
     {
         Visit(relation.TargetEntityElementConfig, visitor);
     }
     visitor(entityConfig);
 }
 public EntityRelationElementBuilder DirectTo(EntityElementBuilder entityElementBuilder)
 {
     _targetEntityElement       = null;
     _targetEntityElementConfig = entityElementBuilder;
     return(this);
 }