Public Function ContainsKey( _
   ByVal key As TKey _
) As Boolean

public bool ContainsKey( 
   TKey key
)

using (BPlusTree<int, string> tree = Create(Options))
{
    tree.EnableCount();
    Assert.AreEqual(0, tree.Count);
    tree.Rollback();
    Assert.AreEqual(0, tree.Count);
    tree.Commit();
    Assert.AreEqual(0, tree.Count);

    tree.Add(1, "A");
    tree.Rollback();
    Assert.AreEqual(0, tree.Count);
    tree.Commit();
    Assert.AreEqual(0, tree.Count);

    tree.Add(1, "A");
    tree.Commit();
    Assert.AreEqual(1, tree.Count);
    tree.Rollback();
    Assert.AreEqual(1, tree.Count);

    tree.Add(2, "B");
    tree.Rollback();
    Assert.AreEqual(1, tree.Count);
    tree[1] = "abc";
    tree.Commit();
    Assert.AreEqual(1, tree.Count);
    tree.Rollback();

    Assert.AreEqual("abc", tree[1]);
    Assert.IsFalse(tree.ContainsKey(2));
}

Using tree As BPlusTree(Of Integer, String) = Create(Options)
    tree.EnableCount()
    Assert.AreEqual(0, tree.Count)
    tree.Rollback()
    Assert.AreEqual(0, tree.Count)
    tree.Commit()
    Assert.AreEqual(0, tree.Count)

    tree.Add(1, "A")
    tree.Rollback()
    Assert.AreEqual(0, tree.Count)
    tree.Commit()
    Assert.AreEqual(0, tree.Count)

    tree.Add(1, "A")
    tree.Commit()
    Assert.AreEqual(1, tree.Count)
    tree.Rollback()
    Assert.AreEqual(1, tree.Count)

    tree.Add(2, "B")
    tree.Rollback()
    Assert.AreEqual(1, tree.Count)
    tree(1) = "abc"
    tree.Commit()
    Assert.AreEqual(1, tree.Count)
    tree.Rollback()

    Assert.AreEqual("abc", tree(1))
    Assert.IsFalse(tree.ContainsKey(2))
End Using