public bool ContainsNodeAfterAddition()
{
// arrange
var allNodes = _nodeRepository.GetAll().ToList();
var allEdges = _edgeRepository.GetAll().ToList();
EdgeEntity edge = allEdges.PickRandomElem();
NodeEntity fromNode = allNodes.PickRandomElem();
NodeEntity toNode = allNodes.PickRandomElem();
// act
int newRelationId = _relationRepository.AddRelation(edge.Id, fromNode.Id, toNode.Id);
var allRelations = _relationRepository.GetAll();
// assert
return(allRelations.Any(r =>
r.Id == newRelationId &&
r.EdgeId == edge.Id &&
r.FromNodeId == fromNode.Id &&
r.ToNodeId == toNode.Id));
}
