Because it includes a Go pointer, the memory it points to is only pinned
for the duration of the call; _GoString_ values may not be retained by C
code.

A Go function called by C code may return a Go pointer to pinned memory
(which implies that it may not return a string, slice, channel, and so
forth). A Go function called by C code may take C pointers as arguments,
and it may store non-pointer data, C pointers, or Go pointers to pinned

the function call.
</p>

<p>
The final case, a value-receiver function for a pointer-receiver method,
is illegal because pointer-receiver methods are not in the method set
of the value type.
</p>

<p>
Function values derived from methods are called with function call syntax;
the receiver is provided as the first argument to the call.

		line, isPrefix, err := b.ReadLine()
		if !bytes.Equal(line, e.line) {
			t.Errorf("%q call %d, line == %q, want %q", input, i, line, e.line)
			return
		}
		if isPrefix != e.isPrefix {
			t.Errorf("%q call %d, isPrefix == %v, want %v", input, i, isPrefix, e.isPrefix)
			return
		}
		if err != e.err {
			t.Errorf("%q call %d, err == %v, want %v", input, i, err, e.err)
			return
		}
	}
}

var callbackMutex sync.Mutex
var callbackToken int
var callbackFuncs = make(map[int]func())

// nestedCall calls into C, back into Go, and finally to f.
func nestedCall(f func()) {
	// callback(x) calls goCallback(x)
	callbackMutex.Lock()
	callbackToken++
	i := callbackToken
	callbackFuncs[i] = f
	callbackMutex.Unlock()

// The recover built-in function allows a program to manage behavior of a
// panicking goroutine. Executing a call to recover inside a deferred
// function (but not any function called by it) stops the panicking sequence
// by restoring normal execution and retrieves the error value passed to the
// call of panic. If recover is called outside the deferred function it will
// not stop a panicking sequence. In this case, or when the goroutine is not

`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

Second, the timer channel associated with a `Timer` or `Ticker` is
now unbuffered, with capacity 0.
The main effect of this change is that Go now guarantees
that for any call to a `Reset` or `Stop` method, no stale values

execution terminates by returning to its caller.
</p>

<p>
The return value of <code>recover</code> is <code>nil</code> when the
goroutine is not panicking or <code>recover</code> was not called directly by a deferred function.
Conversely, if a goroutine is panicking and <code>recover</code> was called directly by a deferred function,

//
// Buffer panics if it is called after scanning has started.
func (s *Scanner) Buffer(buf []byte, max int) {
	if s.scanCalled {
		panic("Buffer called after Scan")
	}
	s.buf = buf[0:cap(buf)]
	s.maxTokenSize = max
}

// Split sets the split function for the [Scanner].
// The default split function is [ScanLines].
//
// Split panics if it is called after scanning has started.

	io.Writer
	fileState

	ReadFrom(io.Reader) (int64, error)
}

// Flush finishes writing the current file's block padding.
// The current file must be fully written before Flush can be called.
//
// This is unnecessary as the next call to [Writer.WriteHeader] or [Writer.Close]
// will implicitly flush out the file's padding.
func (tw *Writer) Flush() error {
	if tw.err != nil {
		return tw.err
	}

	// "SCHILY.xattr." namespace.
	//
	// The following are semantically equivalent:
	//  h.Xattrs[key] = value
	//  h.PAXRecords["SCHILY.xattr."+key] = value
	//
	// When Writer.WriteHeader is called, the contents of Xattrs will take
	// precedence over those in PAXRecords.
	//
	// Deprecated: Use PAXRecords instead.
	Xattrs map[string]string

	// PAXRecords is a map of PAX extended header records.
	//