The method assertInternalType() does not seem to exist on object<hipanel\modules\f...s\TariffControllerTest>.
This check looks for calls to methods that do not seem to exist on a given type.
It looks for the method on the type itself as well as in inherited classes or
implemented interfaces.
This is most likely a typographical error or the method has been renamed.
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: