This can cause long file names (URLs) to be truncated which in turn will break named hooks code (since it needs to load those file names).
This refinement is for Flow purposes only.
    const refinedID = ((id: any): number);
     Make sure we're tracking this Fiber
     e.g. if it just mounted or an error was logged during initial render.
    if (!fiberToIDMap.has(fiber)) {
      fiberToIDMap.set(fiber, refinedID);
      idToArbitraryFiberMap.set(refinedID, fiber);
    }
     Also make sure we're tracking its alternate,
     e.g. in case this is the first update after mount.
    const {alternate} = fiber;
    if (alternate !== null) {
      if (!fiberToIDMap.has(alternate)) {
        fiberToIDMap.set(alternate, refinedID);
      }
    }
    if (__DEBUG__) {
      if (didGenerateID) {
        debug(
          'getOrGenerateFiberID()',
          fiber,
          fiber.return,
          'Generated a new UID',
        );
      }
    }
    return refinedID;
  }
   Returns an ID if one has already been generated for the Fiber or throws.
  function getFiberIDThrows(fiber: Fiber): number {