public function testFirst()
 {
     // from js
     $this->assertEquals(1, __u::first(array(1, 2, 3)), 'can pull out the first element of an array');
     $this->assertEquals(array(), __u::first(array(1, 2, 3), 0), 'can pass an index to first');
     $this->assertEquals(array(1, 2), __u::first(array(1, 2, 3), 2), 'can pass an index to first');
     $this->assertEquals(1, __u(array(1, 2, 3))->first(), 'can perform OO-style "first()"');
     $result = __u::map(array(array(1, 2, 3), array(1, 2, 3)), function ($vals) {
         return __u::first($vals);
     });
     $this->assertEquals(array(1, 1), $result, 'works well with _.map');
     $func = function () {
         return __u::first(func_get_args());
     };
     $result = $func(4, 3, 2, 1);
     $this->assertEquals(4, $result, 'works on an arguments object');
     // extra
     $this->assertEquals(array(1), __u::first(array(1, 2, 3), 1), 'can pass an index of 1 to first');
     $this->assertEquals(array(4, 5), __u(array(4, 5, 6, 7))->first(2), 'can perform OO-style "first()" with index passed');
     $this->assertEquals(1, __u::head(array(1, 2, 3)), 'aliased as "head"');
     $this->assertEquals(array(), __u::head(array(1, 2, 3), 0), 'aliased as "head"');
     // docs
     $this->assertEquals(5, __u::first(array(5, 4, 3, 2, 1)));
     $this->assertEquals(array(5, 4, 3), __u::first(array(5, 4, 3, 2, 1), 3));
 }
 public function testUniqueId()
 {
     // docs
     $this->assertEquals(0, __u::uniqueId());
     $this->assertEquals('stooge_1', __u::uniqueId('stooge_'));
     $this->assertEquals(2, __u::uniqueId());
     // from js
     $ids = array();
     $i = 0;
     while ($i++ < 100) {
         array_push($ids, __u::uniqueId());
     }
     $this->assertEquals(count($ids), count(__u::uniq($ids)));
     // extra
     $this->assertEquals('stooges', join('', __u::first(__u::uniqueId('stooges'), 7)), 'prefix assignment works');
     $this->assertEquals('stooges', join('', __u(__u('stooges')->uniqueId())->first(7)), 'prefix assignment works in OO-style call');
     while ($i++ < 100) {
         array_push($ids, __u()->uniqueId());
     }
     $this->assertEquals(count($ids), count(__u()->uniq($ids)));
 }