public void DoesntAssociateWithoutTwoGuids()
        {
            var entity = new Entity
            {
                Id          = Guid.NewGuid(),
                LogicalName = "contact",
                Attributes  = new AttributeCollection
                {
                    { "interest", new EntityReference("interest", Guid.NewGuid()) }
                }
            };

            DataWriterService.AssociateManyToMany(entity);

            Service.Verify(s => s.Associate("interest", It.IsAny <Guid>(), It.IsAny <Relationship>(), It.IsAny <EntityReferenceCollection>()), Times.Never());
        }