title: Flutter, floating action button margin of Scaffold
body: <p>I'm trying to build a custom implementation for flutter of the <code>FloatingActionButton</code>, something to replace the standard widget on the <code>Scaffold.floatingActionButton</code> attribute.</p>
  
  <p>The problem is that there is a 16 bottom right margin whatever I try to render within that field, and the only workaround I found is to set that margin to zero in the Scaffold class in the flutter library.</p>
  
  <p>Did anyone found a better solution?</p>