public void op_Length_stringsEmpty(int expected,
                                           string value)
        {
            var obj = new KeyStringDictionary
            {
                new KeyStringPair("A", value)
            };

            var actual = obj.Length();

            Assert.Equal(expected, actual);
        }
        public void op_Length_strings(int expected,
                                      string keys)
        {
            var obj = new KeyStringDictionary
            {
                new KeyStringPair("A", "1"),
                new KeyStringPair("B", string.Empty),
                new KeyStringPair("C", "3"),
                new KeyStringPair("D", string.Empty)
            };

            var actual = obj.Length(keys.Split(',', StringSplitOptions.RemoveEmptyEntries));

            Assert.Equal(expected, actual);
        }