title: Leading=true in debounce not performing as expected
body: <p>Using lodash's <code>debounce()</code>, I'm waiting 10 seconds before setting a search term in my app's state. But I want to set <code>searching</code> in my app's state before I debounce:</p>
  
  <pre><code>onChangeText(text) {
      setSearching(true);
      setSearchTerm(text);
  }
  render(){
      return(
          &lt;TextInput style={s.input}
              onChangeText={_.debounce(this.onChangeText, 10000, {'leading':true} )}
          /&gt;
      )
  }
  </code></pre>
  
  <p><a href="https://lodash.com/docs/4.17.10#debounce" rel="nofollow noreferrer">From the docs</a>, this should run on the leading edge of the timeout, and not until the events stop for the allotted wait time. <strong>The actual behavior is as if there is not debounce at all, the events run each time as they are called without a 10 second buffer. Any ideas?</strong> Removing the <code>{'leading':true}</code> does do the debounce appropriately, but I need to set state in my app before the 10 seconds.</p>