/// <summary>
/// Finds a key-value mapping associated with the greatest key strictly less than the given key.
/// Outputs the valuePair if found and returns true. Otherwise, returns false.
/// </summary>
/// <param name="key"></param>
/// <param name="valuePair"></param>
/// <returns></returns>
public bool TryLessThan(
TK1 key,
out KeyValuePair <TK1, TV1> valuePair)
{
if (_subDictionaryOrdered.TryLessThan(KeyIn(key), out var kvp))
{
valuePair = new KeyValuePair <TK1, TV1>(KeyOut(kvp.Key), ValueOut(kvp.Value));
return(true);
}
valuePair = default;
return(false);
}