JiraApiHelper is a wrapper around the .net jira api, with a function to get all users by iterating over the alphabet

JiraApiHelper.cs

    public class JiraApiHelper
    {
        private readonly Jira inner_client;

        public JiraApiHelper()
        {
            this.inner_client = Jira.CreateRestClient("JiraUrl", "UserName", "Password");
        }

        public List<User> GetAllUsers()
        {
            var users = new List<User>();
            foreach (var item in "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z".Split(','))
            {
                var search_result = inner_client.RestClient.ExecuteRequest<List<User>>(Method.GET,
                    $"/rest/api/2/user/search?username={item}");

                foreach (var user in search_result)
                {
                    if (!users.Any(x => x.Key.Equals(user.Key, StringComparison.CurrentCultureIgnoreCase)))
                    users.Add(user);
                }
            }
            return users;
        }
    }