public Ds\Deque Ds\Deque::map( callable $callback )

<?php 
   deque = new \Ds\Deque([1, 2, 3, 4, 5]);    echo("The elements in deque: \n"); 

   print_r(deque); 
   print_r(deque->map(function(element) {
      return $element * 10; 
   }));
?>

<?php 
   deque = new \Ds\Deque([10, 20, 30, 40, 50]);   echo("The elements in deque: \n"); 

   print_r(deque); 
   print_r(deque->map(function(element) { 
      return $element / 10; 
   })); 
?>