public void CanRemoveCompleteFirstLevel()
{
var key1 = 5;
var key21 = "key1";
var key22 = "key2";
var key12 = 2;
var dictionary = new DoubleKeyDictionary <int, string, string>();
dictionary.Add(key1, key21, "value11");
dictionary.Add(key1, key22, "value2");
dictionary.Add(key12, key21, "value3");
dictionary.Add(key12, key22, "value4");
var result = dictionary.Remove(key1);
result.Should().BeTrue();
dictionary.Count.Should().Be(2);
dictionary.Contains(key1, key21).Should().BeFalse();
dictionary.Contains(key1, key22).Should().BeFalse();
dictionary.GetAll().FirstOrDefault(x => x == "value11").Should().BeNullOrEmpty();
dictionary.GetAll().FirstOrDefault(x => x == "value2").Should().BeNullOrEmpty();
}