* Returns the `Query` instance this observer is currently observing.

* Returns the default options registered for queries whose query key partially matches the * given `queryKey`, via {@link QueryClient#setQueryDefau

* Asynchronous method to fetch and cache a query, resolving with the data or throwing with * the error. * * If the query already exists in th

* Sets default options for mutations whose mutation key partially matches the given * `mutationKey`. As with {@link QueryClient#setQueryDefaults},

* Synchronous way to immediately update the cached data of multiple queries at once, using * filters or partial query key matching. Only queries th

* @deprecated Use queryClient.infiniteQuery(options) instead. This method will be removed in the next major version.

* Returns the default options registered for mutations whose mutation key partially matches * the given `mutationKey`, via {@link QueryClient#setMu

* @deprecated Use queryClient.query(options) instead. You can swallow errors with `.catch(noop)`. This method will be removed in the next major versio

* Resets the query back to its initial state (the state it had when it was * first created, e.g. any `initialData`), destroying it first to cancel

* Resumes mutations that were paused because there was no network connection. Does nothing * (resolving immediately) if the client is currently off

* Replaces the set of queries being observed. Existing `QueryObserver`s * are reused for queries that match an already-observed query hash; * ob

* Cancels the query's currently in-flight fetch, if any. * - Returns a promise that resolves once the cancellation has settled. * - If no fetch

* Fetches the previous page of the infinite query and returns a promise * that resolves with the resulting `InfiniteQueryObserverResult`. The page

* Returns `true` if the query is stale. * - If the query has observers, defers to whether any observer's current * result reports `isStale` (w

* @deprecated Use queryClient.infiniteQuery(options) instead. You can swallow errors with `.catch(noop)`. This method will be removed in the next majo

* `setOnline` can be used to manually set the online state. * * @example * ```ts * import { onlineManager } from '@tanstack/query-core'

@internal

* Resumes a mutation that is currently paused or was restored from a * dehydrated, still-`pending` state. * * - If this mutation has an activ

* `setTimeout` schedules a callback to run after approximately `delay` * milliseconds, like the global `setTimeout` function. The callback can be

* Wraps a `QueryObserverResult` in a `Proxy` that records which properties are read, via * {@link QueryObserver#trackProp} (and an optional `onProp

* Fetches a query defined by the given options without affecting this * observer's own tracked query or result, and returns a promise that * res

* `isOnline` can be used to get the current online state.

@internal

* `setFocused` can be used to manually set the focus state. Set `undefined` * to fall back to the default focus check. * * @example * ```t

* The mutation counterpart of {@link QueryClient#defaultQueryOptions}. Called by framework * adapters (e.g. inside `useMutation`) to merge `queryCl

* Returns the default options that were set when creating the client, or via * {@link QueryClient#setDefaultOptions}. * * @example * ```ts

* Returns the underlying `QueryObserver` instances this observer manages, * in the same order as the queries passed to the constructor or * `set

* Returns `true` if the query's data is stale relative to the given * `staleTime` (defaults to `0`). * - A query with no data is always stale.

@internal