Type Alias EntityKeysWithIncludedAssociations<T, P>

EntityKeysWithIncludedAssociations: {
    [K in P]: T[K] extends default
        ? EntityAttributesOnly<T>
        : T[K] extends default[] ? EntityAttributesOnly<T[K][number]>[] : T[K]
}

Given an entity type T and a set of keys, produce the output type that augments the entity attributes with included associations.