title: Unhandled Exception: Converting object to an encodable object failed: Photography
body: <p>my cloud_firestore looks like this:</p>
  
  <blockquote>
    <p>all_images:{imageUrl:[]}, couplePhoto:String, female:String,
    image_url:String, info:String, male:String</p>
  </blockquote>
  
  <p>my model class: </p>
  
  <pre><code>import 'package:json_annotation/json_annotation.dart';
  part 'Model.g.dart';
  
  @JsonSerializable()
  class Photography {
    final List&lt;AllImages&gt; all_images;
    final String couplePhoto;
    final String female;
    final String image_url;
    final String info;
    final String male;
  
    Photography(this.all_images, this.couplePhoto, this.female, this.image_url,
        this.info, this.male);
  
    factory Photography.fromJson(Map&lt;String, dynamic&gt; json) =&gt;
        _$PhotographyFromJson(json);
  
    Map&lt;String, dynamic&gt; toJson() =&gt; _$PhotographyToJson(this);
  }
  
  @JsonSerializable()
  class AllImages {
    final List&lt;String&gt; imageUrl;
  
    AllImages(this.imageUrl);
  
    factory AllImages.fromJson(Map&lt;String, dynamic&gt; json) =&gt;
        _$AllImagesFromJson(json);
  
    Map&lt;String, dynamic&gt; toJson() =&gt; _$AllImagesToJson(this);
  }
  </code></pre>
  
  <p>Currently, I haven't adminPanel to data insert. so, now I need to read data.
  When running this database, the error is coming in here.</p>
  
  <pre><code>    Future&lt;Photography&gt; postsMap = Firestore.instance
          .collection('photography')
          .document("0yUc5QBGHNNq6WK9CyyF")
          .setData(jsonDecode(jsonEncode(Photography)));
  </code></pre>