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const SUSPENSE_PROMISE = Symbol()
interface SuspensePromiseExtra {  b: Promise<unknown> // base promise  o: Promise<void> // original promise  c: (() => void) | null // cancel promise (null if already cancelled)}
// Not exported for public APIexport type SuspensePromise = Promise<void> & {  [SUSPENSE_PROMISE]: SuspensePromiseExtra}
export const isSuspensePromise = (  promise: Promise<void>): promise is SuspensePromise =>  !!(promise as SuspensePromise)[SUSPENSE_PROMISE]
export const isSuspensePromiseAlreadyCancelled = (  suspensePromise: SuspensePromise) => !suspensePromise[SUSPENSE_PROMISE].c
export const cancelSuspensePromise = (suspensePromise: SuspensePromise) => {  const { b: basePromise, c: cancelPromise } = suspensePromise[SUSPENSE_PROMISE]  if (cancelPromise) {    cancelPromise()    promiseAbortMap.get(basePromise)?.()  }}
// Note: this is a special equality functionexport const isEqualSuspensePromise = (  oldSuspensePromise: SuspensePromise,  newSuspensePromise: SuspensePromise): boolean => {  const oldOriginalPromise = oldSuspensePromise[SUSPENSE_PROMISE].o  const newOriginalPromise = newSuspensePromise[SUSPENSE_PROMISE].o  return (    oldOriginalPromise === newOriginalPromise ||    oldSuspensePromise === newOriginalPromise ||    (isSuspensePromise(oldOriginalPromise) &&      isEqualSuspensePromise(oldOriginalPromise, newSuspensePromise))  )}
export const createSuspensePromise = (  basePromise: Promise<unknown>,  promise: Promise<void>): SuspensePromise => {  const suspensePromiseExtra: SuspensePromiseExtra = {    b: basePromise,    o: promise,    c: null,  }  const suspensePromise = new Promise<void>((resolve) => {    suspensePromiseExtra.c = () => {      suspensePromiseExtra.c = null      resolve()    }    promise.finally(suspensePromiseExtra.c)  }) as SuspensePromise  suspensePromise[SUSPENSE_PROMISE] = suspensePromiseExtra  return suspensePromise}
const promiseAbortMap = new WeakMap<Promise<unknown>, () => void>()
export const registerPromiseAbort = (  basePromise: Promise<unknown>,  abort: () => void) => {  promiseAbortMap.set(basePromise, abort)}