title: How to represent a common Object type in Flow?
body: <p><code>var obj: Object;</code>
  seems to work, but I couldn't find this syntax in docs. Or should I see it as a class type for Object?</p>
  
  <p>PS: by common Object type, I mean a value of this type should satisfy:</p>
  
  <pre><code>value &amp;&amp; typeof value === 'object'
  </code></pre>