A$this->benchmark->mark('end');
// something happens here
$this->benchmark->mark('start');
echo $this->benchmark->elapsed_time('start', 'end');
B$this->benchmark->mark('start');
// something happens here
$this->benchmark->mark('end');
echo $this->benchmark->elapsed_time('start', 'end');
C$this->benchmark->mark('end');
// something happens here
$this->benchmark->mark('start');
echo $this->benchmark->current_time('start', 'end');
D$this->benchmark->mark('start');
// something happens here
$this->benchmark->mark('end');
echo $this->benchmark->elapsed_time('end', 'start');