public void Intersperse ()
{
#region Intersperse
Assert.AreEqual ("1929394", new[]{1,2,3,4}.Intersperse (9).Implode ());
Assert.AreEqual ("a.z", new[]{'a','z'}.Intersperse ('.').Implode ());
IEnumerable<IEnumerable<char>> e = new char[][]{
new char[]{'b', 'c', 'd'},
new char[]{'e', 'f', 'g'},
};
IEnumerable<char> x = new char[]{'a', 'a'};
Assert.AreEqual ("bcdaaefg", e.Intersperse (x).Implode ());
#endregion
}