* Don't show "context" for classes without either contextType or contextTypes
* For classes with contextTypes, change the label to "legacy context" instead

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Originally reported by @gaearon via https://github.com/bvaughn/react-devtools-experimental/issues/368
return alternate;
    }
    primaryFibers.add(fiber);
    return fiber;
  }
  const fiberToIDMap: Map<Fiber, number> = new Map();
  const idToFiberMap: Map<number, Fiber> = new Map();
  const primaryFibers: Set<Fiber> = new Set();
   When profiling is supported, we store the latest tree base durations for each Fiber.
   This is so that we can quickly capture a snapshot of those values if profiling starts.
   If we didn't store these values, we'd have to crawl the tree when profiling started,
   and use a slow path to find each of the current Fibers.
  const idToTreeBaseDurationMap: Map<number, number> = new Map();
   When profiling is supported, we store the latest tree base durations for each Fiber.
   This map enables us to filter these times by root when sending them to the frontend.
  const idToRootMap: Map<number, number> = new Map();
   When a mount or update is in progress, this value tracks the root that is being operated on.
  let currentRootID: number = -1;
  function getFiberID(primaryFiber: Fiber): number {
    if (!fiberToIDMap.has(primaryFiber)) {
      const id = getUID();
      fiberToIDMap.set(primaryFiber, id);
      idToFiberMap.set(id, primaryFiber);
    }
    return ((fiberToIDMap.get(primaryFiber): any): number);
  }
  function getChangeDescription(
    prevFiber: Fiber | null,
    nextFiber: Fiber,
  ): ChangeDescription | null {