setCustomUserAvatar 
  @ExperimentalApi 
  void setCustomUserAvatar(ApplicationUser remoteUser, 
                                            ApplicationUser user, 
                                            Long avatarId) 
                                     throws AvatarsDisabledException, 
                                            NoPermissionException 
  Sets a custom avatar for a given user. 
  Parameters: 
  remoteUser - a User object for the currently logged in user 
  user - the user whose avatar we will configure 
  avatarId - the id of the avatar to configure for the user 
  Throws: 
  AvatarsDisabledException - if avatars are disabled 
  NoPermissionException - if the remote user does not have permission to update the given user's avatar 
  Since: 
  v6.0 
  See Also: 
  #canSetCustomUserAvatar(com.atlassian.crowd.embedded.api.User, String)

@ExperimentalApi 
  boolean canSetCustomUserAvatar(ApplicationUser remoteUser, 
                                                  ApplicationUser user) 
  Returns a boolean indicating whether the calling user can edit the custom user avatar for the user with the given username. 
  Parameters: 
  remoteUser - a User object for the currently logged in user 
  user - the user whose avatar we will configure 
  Returns: 
  a indicating whether the calling user can edit the custom user avatar for another user 
  Since: 
  v6.0

using System; 
  using System.Collections.Generic; 
  using System.Linq; 
  using System.Text; 
  using System.Threading.Tasks; 
  using Atlassian; 
  using Atlassian.Jira; 
  using System.Net; 
  using System.IO; 
   
  namespace ConsoleApplication14 
  { 
      public enum JiraResource 
      { 
          project 
      } 
   
      public class JiraManager 
      { 
          private const string m_BaseUrl = "http://localhost.:8080/rest/api/latest/"; 
          private string m_Username; 
          private string m_Password; 
   
          public JiraManager(string username, string password) 
          { 
              m_Username = username; 
              m_Password = password; 
          } 
   
          public void RunQuery( 
              JiraResource resource, 
              string argument = null, 
              string data = null, 
              string method = "GET") 
          { 
              string url = string.Format("{0}{1}/", m_BaseUrl, resource.ToString()); 
   
              if (argument != null) 
              { 
                  url = string.Format("{0}{1}/", url, argument); 
              } 
   
              HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest; 
              request.ContentType = "application/json"; 
              request.Method = method; 
   
              if (data != null) 
              { 
                  using (StreamWriter writer = new StreamWriter(request.GetRequestStream())) 
                  { 
                      writer.Write(data); 
                  } 
              } 
   
              string base64Credentials = GetEncodedCredentials(); 
              request.Headers.Add("Authorization", "Basic " + base64Credentials); 
   
              HttpWebResponse response = request.GetResponse() as HttpWebResponse; 
   
              string result = string.Empty; 
              using (StreamReader reader = new StreamReader(response.GetResponseStream())) 
              { 
                  result = reader.ReadToEnd(); 
              } 
   
              Console.WriteLine(result); 
          } 
   
          private string GetEncodedCredentials() 
          { 
              string mergedCredentials = string.Format("{0}:{1}", m_Username, m_Password); 
              byte[] byteCredentials = UTF8Encoding.UTF8.GetBytes(mergedCredentials); 
              return Convert.ToBase64String(byteCredentials); 
          } 
      } 
      class Program 
      { 
          static void Main(string[] args) 
          { 
              Console.WriteLine("Hello and welcome to a Jira Example application!"); 
   
              Console.Write("Username: "); 
              string username = Console.ReadLine(); 
   
              Console.Write("Password: "); 
              string password = Console.ReadLine(); 
   
              JiraManager manager = new JiraManager(username, password); 
              manager.RunQuery(JiraResource.project); 
   
              Console.Read(); 
          } 
      } 
  }