arangosh> db.example.first();
{ 
  <span class="hljs-string">"_id"</span> : <span class="hljs-string">"example/4209024955"</span>, 
  <span class="hljs-string">"_key"</span> : <span class="hljs-string">"4209024955"</span>, 
  <span class="hljs-string">"_rev"</span> : <span class="hljs-string">"4209024955"</span>, 
  <span class="hljs-string">"Hello"</span> : <span class="hljs-string">"world"</span> 
}