ription">
   [Read-only] The sender's <code>userID</code>.</div>
</td><td class="summaryTableOwnerCol">ChatMessageDescriptor</td>
</tr>
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<td class="summaryTablePaddingCol">&nbsp;</td><td class="summaryTableInheritanceCol">&nbsp;</td><td class="summaryTableSignatureCol"><a class="signatureLink" href="#recipient">recipient</a> : String<div class="summaryTableDescription">
   For private messages intended for a specific recipient, an optional 
   recipient <code>userID</code>.</div>
</td><td class