title: Write special characters to yaml file
body: <p>im using snakeyaml 1.27</p>
  <p>i want to write special characters to a yaml file:</p>
  <pre class="lang-js prettyprint-override"><code>section.put(&quot;Success&quot;, &quot;\uD83D\uDE03&quot;); 
  section.put(&quot;Warning&quot;, &quot;\uD83D\uDE2E&quot;); 
  section.put(&quot;Error&quot;, &quot;\uD83D\uDE26&quot;); 
  </code></pre>
  <p>but the output is either</p>
  <pre class="lang-js prettyprint-override"><code>  Success: ?
    Warning: ?
    Error: ?
  </code></pre>
  <p>or</p>
  <pre class="lang-js prettyprint-override"><code>  Success: &quot;\U0001f603&quot;
    Warning: &quot;\U0001f62e&quot;
    Error: &quot;\U0001f626&quot;
  </code></pre>
  <p>if i change
  <code>DumperOptions().setAllowUnicode(true/false);</code></p>
  <p>If i just read and write a yaml the same thing appears.
  its able to read the  but not write it back.</p>
  <p>code:</p>
  <pre class="lang-js prettyprint-override"><code>DumperOptions o = new DumperOptions();
  o.setPrettyFlow(true);
  o.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
  o.setAllowUnicode(true);
  
  Yaml yaml = new Yaml(o);
  InputStream is = new FileInputStream(file);
  Map&lt;String, Object&gt; data = yaml.load(is);
  is.close();
  
  StringWriter writer = new StringWriter();
  yaml.dump(data, writer);
  
  FileWriter fw = new FileWriter(file);
  fw.write(writer.toString());
  fw.close();
  </code></pre>
  <p>yaml before:</p>
  <pre class="lang-js prettyprint-override"><code>Bot_Token: f1432d2asdummy
  Owner_ID: '123456'
  Command_Trigger: '-'
  Game: Ready  playing music. !Play
  Emojis:
    Success: 
    Warning: 
    Error: 
  </code></pre>
  <p>yaml after:</p>
  <pre class="lang-js prettyprint-override"><code>Bot_Token: f1432d2asd3dummy
  Owner_ID: '123456'
  Command_Trigger: '-'
  Game: Ready  playing music. !Play
  Emojis:
    Success: ?
    Warning: ?
    Error: ?
  </code></pre>