//<age> public string Execute(params string[] args) { var age = int.Parse(args[0]); var infoEmployee = employeeService.GetEmployeeOlderThan(age); if (infoEmployee == null || infoEmployee.Length == 0) { throw new ArgumentException($"There are not employees older than {age}"); } var sb = new StringBuilder(); foreach (var employee in infoEmployee.OrderByDescending(x => x.Salary)) { if (employee.Manager != null) { sb.AppendLine($"{employee.FirstName} {employee.LastName} - ${employee.Salary:f2} - Manager: {employee.Manager.LastName}"); } else { sb.AppendLine($"{employee.FirstName} {employee.LastName} - ${employee.Salary:f2} - Manager: [no manager]"); } } return(sb.ToString().Trim()); }