## The current behavior

The full value of the `key` is very difficult / impossible to find and use in the interface of the React Devtools.

![Kapture 2020-04-22 at 11 47 47](https://user-images.githubusercontent.com/1935696/79997715-25222680-84ba-11ea-97ba-51f1679a8c91.gif)

Only managed to find it by accident :(

## The expected behavior

The `key` is visible in the props list to the right.

### Detailed Proposal

As mentioned below in https://github.com/facebook/react/issues/18702#issuecomment-617924196

Add a light divider and new section in the props panel to the right.

Potentially also add a question mark that shows an explanation about the fact that things in this section are not really props.

Ref (Original implementation): https://github.com/facebook/react-devtools/pull/328
if (internalInstance._currentElement != null) {
    const elementType = internalInstance._currentElement.type;
    if (typeof elementType === 'function') {
      const publicInstance = internalInstance.getPublicInstance();
      if (publicInstance !== null) {
        return ElementTypeClass;
      } else {
        return ElementTypeFunction;
      }
    } else if (typeof elementType === 'string') {
      return ElementTypeHostComponent;
    }
  }
  return ElementTypeOtherOrUnknown;
}
function getChildren(internalInstance: Object): Array<any> {