It seems like new \IBM\Watson\ToneAnal..., $response->getBody()) of type object<IBM\Watson\ToneAn...r\Message\ToneResponse> is incompatible with the declared type object<Omnipay\Common\Message\ResponseInterface> of property $response.
Our type inference engine has found an assignment to a property that is incompatible
with the declared type of that property.
Either this assignment is in error or the assigned type should be added
to the documentation/type hint for that property..
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: