code: public function invoke($method, $args)
      {
          $method = strtolower($method);
          $step   = $this->getCallCount($method);
          $this->addCall($method, $args);
          $this->checkExpectations($method, $args, $step);
          $was = $this->disableEStrict();
          try {
              $result = $this->emulateCall($method, $args, $step);
          } catch (Exception $e) {
              $this->restoreEStrict($was);
              throw $e;
          }
          $this->restoreEStrict($was);
  
          return $result;
      }
docs: Returns the expected value for the method name and checks expectations.
  Will generate anytest assertions as a result of expectations
  if there is a test present.
  
  @param string $method Name of method to simulate.
  @param array  $args   Arguments as an array.
  
  @return mixed Stored return.