You seemed to have removed this section from the docs but not replaced it with a unittest. E.g.:

```D
///
unittest
{
    assert([0, 2, 1, 5, 0, 3].drop(3) == [5, 0, 3]);
    assert("hello world".drop(6) == "world");
    assert("hello world".drop(50).empty);
    assert("hello world".take(6).drop(3).equal("lo "));

    // Remove all but the first two elements
    auto a = DList!int(0, 1, 9, 9, 9);
    a.remove(a[].drop(2));
    assert(a[].equal(a[].take(2)));

    assert([0, 2, 1, 5, 0, 3].dropBack(3) == [0, 2, 1]);
    assert("hello world".dropBack(6) == "hello");
    assert("hello world".dropBack(50).empty);
    assert("hello world".drop(4).dropBack(4).equal("o w"));

    // insert before the last two elements
    auto a = DList!int(0, 1, 2, 5, 6);
    a.insertAfter(a[].dropBack(2), [3, 4]);
    assert(a[].equal(iota(0, 7)));
}
```