title: error: 3 positional argument(s) expected, but 0 found
body: <p>I already declared my arguments but it says to me that 3 pos. arguments expected but 0 found. Error is at
  <strong>Article.fromJSON</strong> part. Does anybody know why?</p>
  <pre><code>class Article {
    final String id;
    final String caption;
    final DateTime timestamp;
  
    Article(this.id, this.caption, this.timestamp, );
  
  
    factory Article.fromJSON(Map&lt;String, dynamic&gt; jsonMap) {
      return Article(
        id: jsonMap['id'] as String,
        caption: jsonMap['caption'] as String ,
        timestamp: jsonMap['timestamp'] as DateTime ,
        
      );
    }
  
    Map toMap() {
      var map = new Map&lt;String, dynamic&gt;();
      map[&quot;id&quot;] = id;
      map[&quot;caption&quot;] = caption ;
      map[&quot;timestamp&quot;] = timestamp ;
      return map;
    }
    
  }
  </code></pre>