Say, for such an entity defined below, what is the correct response for GET "serviceRoot/entity(1)/nav"? Assuming entity with id 1 has valid values, but its stored key for the 'nav' reference is null.
<EntityType Name="entityType">
<Key>
<PropertyRef Name="id"/>
</Key>
<Property Name="id" Nullable="false" Type="Edm.Integer"/>
<Property Name="name" Nullable="false" Type="Edm.String"/>
<NavigationProperty Name="nav" Nullable="true" Type="this.navType"/>
</EntityType>
<EntityType Name="navType">
<Key>
<PropertyRef Name="navId"/>
</Key>
<Property Name="navId" Nullable="false" Type="Edm.Integer"/>
<Property Name="name" Nullable="false" Type="Edm.String"/>
</EntityType>
<EntityContainer Name="Container">
<EntitySet EntityType="navType" Name="navSet"/>
<EntitySet EntityType="entityType" Name="entity">
<NavigationPropertyBinding Path="nav" Target="this.navSet"/>
</EntitySet>
</EntityContainer>