JIRA REST API, JSON response, C#
<p>I want to get issues from boards and print issues's summary (using JIRA Rest API: <a href="https://docs.atlassian.com/jira-software/REST/cloud/#agile/1.0/board-getIssuesForBoard" rel="nofollow">https://docs.atlassian.com/jira-software/REST/cloud/#agile/1.0/board-getIssuesForBoard</a>), but i don't want to get all issue's fields, - i need fields: "sprint" and "epic".</p>

<p>I have error:</p>

<blockquote>
  <p>Unhandled Exception: System.NullReferenceException: Object reference
  not set to an instance of an object.</p>
</blockquote>

<p>At line:</p>

<pre><code>var response = client.RestClient.ExecuteRequest&lt;ResponseIssues&gt;(Method.GET, 
                        @"/rest/agile/1.0/board/2/issue?fields='epic,sprint'");
</code></pre>

<p>Code (C#):</p>

<pre><code>var client = Atlassian.Jira.Jira.CreateRestClient(jiraurl, login, password);
var response = client.RestClient.ExecuteRequest&lt;ResponseIssues&gt;(Method.GET, 
                       @"/rest/agile/1.0/board/2/issue?fields='epic,sprint'");
foreach (var issue in response.issues)
{
     Console.WriteLine(issue.fields.epic.summary);
}
</code></pre>

<p>Class ResponseIssues (C#):</p>

<pre><code>public class ResponseIssues
{
    public string expand;
    public int startAt;
    public int maxResults;
    public int total;
    public List&lt;Issue_&gt; issues;
}    
public class Issue_
{
    public string expand;
    public string id;
    public string self;
    public string key;
    public Field fields;
}    
public class Field
{
    public Sprint sprint;
    public Epic epic;            
}   
public class Sprint
{
    public int id;
    public string self;
    public string state;
    public string name;
}    
public class Epic
{
    public int id;
    public string self;
    public string name;
    public string summary;
    public Color color;
    public bool done;
}    
public class Color
{
    public string key;
}
</code></pre>