function needs to be wrapped in transaction.
 Returns RetKey, or '$end_of_table' or  throws Error</p>

<h3 class="function"><a name="prev-2">prev/2</a></h3>
<div class="spec">
<p><tt>prev(Storage::atom(), Key::any()) -&gt; RetKey::any() | '$end_of_table' | no_return()</tt><br></p>
</div><p>Previous.
 Function gets the previous key of the Storage, from given Key
 As input function gets Name of storage as atom and pivot Key
 The function needs to be wrapped in transaction.
 Returns RetKey, or '$end_of_table' 