title: OpenAPI Dart generator
body: <p>I'm using OpenAPI generator to generate Dart client to my spec.</p>
  <p>One of my endpoints returns binary data which reflects in schema like this:</p>
  <pre><code>&quot;responses&quot; : {
    &quot;200&quot; : {
      &quot;description&quot; : &quot;&quot;,
      &quot;content&quot; : {
        &quot;application/octet-stream&quot; : {
          &quot;schema&quot; : {
            &quot;type&quot; : &quot;string&quot;,
            &quot;format&quot; : &quot;binary&quot;
          }
        }
      }
    }
  }
  </code></pre>
  <p>Client is generated without errors, with the response type Future. However  when I invoke that method, I get error like this:</p>
  <pre><code>Unhandled exception:
  FormatException: Unexpected character (at character 1)
    
  #0      _ChunkedJsonParser.fail (dart:convert-patch/convert_patch.dart:1404:5)
  #1      _ChunkedJsonParser.parseNumber (dart:convert-patch/convert_patch.dart:1271:9)
  #2      _ChunkedJsonParser.parse (dart:convert-patch/convert_patch.dart:936:22)
  #3      _parseJson (dart:convert-patch/convert_patch.dart:40:10)
  #4      JsonDecoder.convert (dart:convert/json.dart:506:36)
  #5      JsonCodec.decode (dart:convert/json.dart:157:41)
  #6      jsonDecode (dart:convert/json.dart:96:10)
  #7      ApiClient.deserialize (package:openapi/api_client.dart:192:20)
  #8      DefaultApi.testIntPost (package:openapi/api/default_api.dart:143:24)
  &lt;asynchronous suspension&gt;
  #9      main.&lt;anonymous closure&gt; (package:X/run.dart)
  &lt;asynchronous suspension&gt;
  </code></pre>
  <p>What am I doing wrong?</p>