title: Basic FlatList code throws Warning - React Native
body: <p>FlatList does not seem to be working. I get this warning.</p>
  
  <p><strong>VirtualizedList: missing keys for items, make sure to specify a key property on each item or provide a custom keyExtractor.</strong> </p>
  
  <p>Code:</p>
  
  <pre><code>&lt;FlatList 
    data={[{name: 'a'}, {name: 'b'}]} 
    renderItem={
      (item) =&gt; &lt;Text key={Math.random().toString()}&gt;{item.name}&lt;/Text&gt;
    } 
    key={Math.random().toString()} /&gt;
  </code></pre>