func (s *Singleton[T]) IsSet() bool {
	select {
	case <-s.set:
		return true
	default:
		return false
	}
}

// Set the value and unblock all Get requests.
// This may only be called once, a second call will panic.
func (s *Singleton[T]) Set(v *T) {
	s.v = v
	close(s.set)

## Parameterized dependencies

All the dependencies we have seen are a fixed function or class.

But there could be cases where you want to be able to set parameters on the dependency, without having to declare many different functions or classes.

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

But we want to be able to parameterize that fixed content.

</p>
<p>
Implementation restriction: For compatibility with other tools, a
compiler may disallow the NUL character (U+0000) in the source text.
</p>
<p>
Implementation restriction: For compatibility with other tools, a
compiler may ignore a UTF-8-encoded byte order mark
(U+FEFF) if it is the first Unicode code point in the source text.
A byte order mark may be disallowed anywhere else in the source.
</p>

elasticsearch.url: "http://localhost:9201"
```

#### Q. I imported "fess\_log.ndjson" but no results found.

  - the `scheduler.alpha.kubernetes.io/critical-pod` annotation is removed. Pod priority (`spec.priorityClassName`) should be used instead to mark pods as critical. ([#80342](https://github.com/kubernetes/kubernetes/pull/80342), [@draveness](https://github.com/draveness))

    "Accept-Ranges": "bytes",
    "Content-Length": "0",
    "ETag": "9fe7a344ef4227d3e53751e9d88ce41e",
    "Server": "MinIO",
    "Strict-Transport-Security": "max-age=31536000; includeSubDomains",
    "Vary": "Origin,Accept-Encoding",
    "X-Amz-Id-2": "dd9025bab4ad464b049177c95eb6ebf374d3b3fd1af9251148b658df7ac2e3e8",
    "X-Amz-Request-Id": "17CDC1F4D7E69123",
    "X-Content-Type-Options": "nosniff",

/*
 * Copyright 2014 Square Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2012-2024 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2012-2024 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2014 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,