## 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
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      hook.emit('operations', operations);
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    pendingOperations.length = 0;
    pendingRealUnmountedIDs.length = 0;
    pendingSimulatedUnmountedIDs.length = 0;
    pendingUnmountedRootID = null;
    pendingStringTable.clear();
    pendingStringTableLength = 0;
  }
  function getStringID(str: string | null): number {
    if (str === null) {