Override Default Params on QnA Pipeline
How should we override the default params of QnA Model in Pipelines?

I tried the below but it throws an error?!

![image](https://user-images.githubusercontent.com/22409996/107048748-f586a580-67d1-11eb-88fe-f78901d99734.png)
I think you first need to initialize the pipeline, and then call it with any parameters you like. Example:

```
from transformers import pipeline
nlp = pipeline("question-answering")
context = r"""
Extractive Question Answering is the task of extracting an answer from a text given a question. An example of a
question answering dataset is the SQuAD dataset, which is entirely based on that task. If you would like to fine-tune
a model on a SQuAD task, you may leverage the examples/question-answering/run_squad.py script.

result = nlp(question="What is extractive question answering?", context=context, max_answer_len=100)
```

For the documentation of the `__call__` method of `QuestionAnsweringPipeline`, see [here](https://huggingface.co/transformers/main_classes/pipelines.html#transformers.QuestionAnsweringPipeline.__call__).<|||||>This solved my issue. Thank you very much.