public string Execute(IReadOnlyList <string> args)
        {
            if (args.Count != 3)
            {
                throw new ArgumentException("Write 3 parameters separated by (;).");
            }

            var name   = args[0];
            var city   = args[1];
            var league = args[2];

            InputValidations.ValidateLength(InputValidations.MIN_NAME, InputValidations.MAX_NAME, name,
                                            $"Team's name must be between {InputValidations.MIN_NAME} and {InputValidations.MAX_NAME} characters");
            InputValidations.ValidateLength(InputValidations.MIN_NAME, InputValidations.MAX_NAME, city,
                                            $"Team's city must be between {InputValidations.MIN_NAME} and {InputValidations.MAX_NAME} characters");
            InputValidations.ValidateLength(InputValidations.MIN_NAME, InputValidations.MAX_NAME, league,
                                            $"A league's name must be between {InputValidations.MIN_NAME} and {InputValidations.MAX_NAME} characters");
            service.AddTeamToLeague(name, city, league);
            return($"Team {name} {city} has been added to league {league}.");
        }