title: kotlin add method, having difficulty understanding the "it" argument
body: <pre><code>private fun defaultOptions() {
     val options = ArrayList&lt;TextView&gt;() 
     tvoptionone?.let { options.add(0, it) } 
  }
  </code></pre>
  <p>I am currently using the <code>add(index, element)</code> method in kotlin, However, I don't seem to understand what it represents in the element parameter of the add method.</p>
  <p>These are the parameters for the add method I am trying to use</p>
  <pre><code>add(index, element)
  </code></pre>