mock_objects.php
protected function emulateCall($method, $args, $step)
    {
        return $this->actions->respond($step, $method, $args);
    }
protected function emulateCall($method, $args, $step)
    {
        return $this->actions->respond($step, $method, $args);
    }
Finds the return value matching the incoming arguments.
If there is no matching value found, then an error is triggered.

@param string $method Method name.
@param array  $args   Calling arguments.
@param int    $step   Current position in the call history.

@return mixed Stored return or other action.