public void CopyFrom()
{
var source = new CloneableType[] { "a", "b", "c", "d" };
Assert.Throws <NotSupportedException>(() => _readOnly.CopyFrom(source, 1));
Assert.Throws <ArgumentException>(() => _array.CopyFrom(source, 3));
_array.CopyFrom(source, 1);
Assert.AreEqual(new CloneableType("one"), _array[0]);
Assert.AreEqual(new CloneableType("a"), _array[1]);
Assert.AreEqual(new CloneableType("b"), _array[2]);
Assert.AreEqual(new CloneableType("c"), _array[3]);
Assert.AreEqual(new CloneableType("d"), _array[4]);
Assert.AreEqual(new CloneableType("six"), _array[5]);
}