title: Animation duration in React Spring
body: <p>I have a fairly simple fade-in scenario, where I want to control the duration of the animation. But cannot wrap around my head around how to accomplish this.</p>
  
  <p>Code excerpt:</p>
  
  <pre><code>function BoxA() {
    return (
      &lt;Spring from={{ opacity: 0.2 }} to={{ opacity: 1 }}&gt;
        {props =&gt; (
          &lt;div
            style={{
              height: 100,
              width: 100,
              backgroundColor: "pink",
              color: "#fff",
              ...props
            }}
          &gt;
            1
          &lt;/div&gt;
        )}
      &lt;/Spring&gt;
    );
  }
  </code></pre>
  
  <p>Complete code example: <a href="https://codesandbox.io/s/n7pw660264" rel="noreferrer">https://codesandbox.io/s/n7pw660264</a></p>