code: protected function checkExpectations($method, $args, $timing)
      {
          $test = $this->getCurrentTestCase();
          if (isset($this->max_counts[$method])) {
              if (! $this->max_counts[$method]->test($timing + 1)) {
                  $test->assert($this->max_counts[$method], $timing + 1);
              }
          }
          if (isset($this->expected_args_at[$timing][$method])) {
              $test->assert(
                      $this->expected_args_at[$timing][$method],
                      $args,
                      "Mock method [$method] at [$timing] -> %s");
          } elseif (isset($this->expected_args[$method])) {
              $test->assert(
                      $this->expected_args[$method],
                      $args,
                      "Mock method [$method] -> %s");
          }
      }
docs: Tests the arguments against expectations.
  
  @param string $method Method to check.
  @param array  $args   Argument list to match.
  @param int    $timing The position of this call in the call history.