Function defaultProps

defaultProps(target?, props?, overrideNil?): object | undefined
Returns an object that merged the given props, when the key of props is missing, or the value of matching key is null or undefined
Parameters
- Optionaltarget: object
  the object to inspect
- Optionalprops: object
  the properties to assign
- overrideNil: boolean = true
  whether to override the value of target, when it is null or undefined
Returns object | undefined
an object that merged the given props, when the key of props is missing, or the value of matching key is null or undefined
Example
```
defaultProps({}, {'foo': 'bar'});
```