public void GetPermissionsTest()
{
Guid permission1Id = Guid.NewGuid();
Guid permission2Id = Guid.NewGuid();
AddPermission(permission1Id, "Modify");
AddPermission(permission2Id, "Read");
IReadOnlyCollection<Permission> permissions = sut.GetPermissions();
Assert.AreEqual(2, permissions.Count());
Assert.IsNotNull(permissions.SingleOrDefault(p => p.Id == permission1Id));
Assert.IsNotNull(permissions.SingleOrDefault(p => p.Id == permission2Id));
}