public void Concat ()
{
IEnumerable<int> s = new[]{1};
Assert.AreEqual ("1234567",
s.Concat (new[]{2, 3}, new[]{4, 5}, new[]{6, 7}).Implode ());
IEnumerable<IEnumerable<int>> ss = new []{
new[]{2,3},
new[]{4,5},
new[]{6,7},
};
Assert.AreEqual ("1234567", s.Concat (ss).Implode ());
}