abstract public bool Ds\Collection::isEmpty( void )

<?php 
   collection = new \Ds\Vector([10, 15, 20, 25, 30, 35]);res = collection->isEmpty();

   var_dump(res);
   collection = new \Ds\Vector();res = collection->isEmpty();
   var_dump(res);  
?>

<?php 
   collection = new \Ds\Vector();   var_dump(collection->isEmpty());

   collection = new \Ds\Vector([1, 3, 5, 2, 6]);   var_dump(collection->isEmpty());
?>