Commented Issue: Try to use IList, IDictionary or ReadOnlyCollection for returning types [774]

ODataModelBuilder.EntitySets property should be ReadOnlyCollection. same as Procedures and StructuralTypes properties;

Review StructuralTypeConfiguration/StructuralTypeConfiguration<T> as well;

ODataMediaTypeFormatters.Create() should return a IList<ODataMediaTypeFormatters>

Comments: Fixed: http://aspnetwebstack.codeplex.com/SourceControl/changeset/bdb88943a237