/// <summary>
/// upsert edge and ensure to side is unique
/// </summary>
/// <typeparam name="TEdge"></typeparam>
/// <typeparam name="TFrom"></typeparam>
/// <typeparam name="TTo"></typeparam>
/// <param name="arangoDatabase"></param>
/// <param name="from"></param>
/// <param name="to"></param>
/// <param name="setter"></param>
/// <returns></returns>
public static TEdge UpsertEdgeUniqueTo <TEdge, TFrom, TTo>(this IArangoDatabase arangoDatabase, TFrom from, TTo to, Action <TEdge> setter = null) where TEdge : EdgeBase, new() where TFrom : VertexBase where TTo : VertexBase
{
TEdge edge = new TEdge();
edge._from = from.GetId();
edge._to = to.GetId();
edge.BuildIdWithFromTo();
setter?.Invoke(edge);
arangoDatabase.UpsertEdgeUniqueTo(edge);
return(edge);
}