Argument of type 'null' is not assignable to parameter of type 'MappingContextValue'

## 💬 Question

I am new to typescript and trying to lear our code step by step. I use `react-native init` to create a project and type 'them.service.ts'. But my vscode always complain 'Argument of type "null" is not assignable to parameter of type "MappingContextValue'.

I googled and people mentioned: 'restrict null check'. but how can I disable the check. I tried to configure tslint.json etc.

npx react-native --version : 4.10.1