public void op_ToNumberGroups_string_string(string expected,
                                                    string areaCode,
                                                    string telephone)
        {
            var actual = BritishTelephone.ToNumberGroups(areaCode, telephone);

            Assert.Equal(expected, actual);
        }
 public void op_ToNumberGroups_string_stringNull()
 {
     Assert.Throws <ArgumentNullException>(() => BritishTelephone.ToNumberGroups("01234", null));
 }
 public void op_ToNumberGroups_stringNull_string()
 {
     Assert.Empty(BritishTelephone.ToNumberGroups(null, "+441483999999"));
 }
 public void op_ToNumberGroups_stringEmpty_string()
 {
     Assert.Empty(BritishTelephone.ToNumberGroups(string.Empty, "+441483999999"));
 }