public void Number_Method() { Assert.Throws<ArgumentNullException>(() => new LawsLawApiCall().Number(null)); Assert.Throws<ArgumentException>(() => new LawsLawApiCall().Number(string.Empty)); var call = new LawsLawApiCall(); Assert.False(call.Parameters.ContainsKey("number")); Assert.True(ReferenceEquals(call.Number("number"), call)); Assert.Equal("number", call.Parameters["number"]); }