return err
	}
	for _, ifa := range ifat {
		switch v := ifa.(type) {
		case *IPAddr:
			if a := v.IP.To4(); a != nil {
				copy(mreq.Interface[:], a)
				goto done
			}
		case *IPNet:
			if a := v.IP.To4(); a != nil {
				copy(mreq.Interface[:], a)
				goto done
			}
		}
	}
done:
	if bytealg.Equal(mreq.Multiaddr[:], IPv4zero.To4()) {
		return errNoSuchMulticastInterface
	}
	return nil
}

	_Continue    // continue
	_Default     // default
	_Defer       // defer
	_Else        // else
	_Fallthrough // fallthrough
	_For         // for
	_Func        // func
	_Go          // go
	_Goto        // goto
	_If          // if
	_Import      // import
	_Interface   // interface
	_Map         // map
	_Package     // package
	_Range       // range
	_Return      // return
	_Select      // select

		}
		`,
		`
		package p
		type S struct{}
		func (T) _() {}
		func (T) _() {}
		`,
		`
		package p
		func _() {
		L0:
		L1:
			goto L0
			for {
				goto L1
			}
			if true {
				goto L2
			}
		L2:
		}
		`,
	}

	pkgnames := []string{
		"fmt",
		"math",
	}

	// parse package files
	fset := token.NewFileSet()

		}
		`,
		`
		package p
		type S struct{}
		func (T) _() {}
		func (T) _() {}
		`,
		`
		package p
		func _() {
		L0:
		L1:
			goto L0
			for {
				goto L1
			}
			if true {
				goto L2
			}
		L2:
		}
		`,
	}

	pkgnames := []string{
		"fmt",
		"math",
	}

	// parse package files
	var files []*syntax.File

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

func f1() {
exit:
	print("hi\n")
	goto exit
}

func f2() {
	const c = 1234
}

func f3() {
	i := c // ERROR "undef"
	_ = i
}

func main() {
	f3()

	// If there are any forward jumps left, no label was found for
	// the corresponding goto statements. Either those labels were
	// never defined, or they are inside blocks and not reachable
	// for the respective gotos.
	for _, jmp := range fwdJumps {
		var msg string
		var code Code
		name := jmp.Label.Name
		if alt := all.Lookup(name); alt != nil {
			msg = "goto %s jumps into block"
			code = JumpIntoBlock

	// If there are any forward jumps left, no label was found for
	// the corresponding goto statements. Either those labels were
	// never defined, or they are inside blocks and not reachable
	// for the respective gotos.
	for _, jmp := range fwdJumps {
		var msg string
		var code Code
		name := jmp.Label.Value
		if alt := all.Lookup(name); alt != nil {
			msg = "goto %s jumps into block"
			code = JumpIntoBlock

	CONTINUE: "continue",

	DEFAULT:     "default",
	DEFER:       "defer",
	ELSE:        "else",
	FALLTHROUGH: "fallthrough",
	FOR:         "for",

	FUNC:   "func",
	GO:     "go",
	GOTO:   "goto",
	IF:     "if",
	IMPORT: "import",

	INTERFACE: "interface",
	MAP:       "map",
	PACKAGE:   "package",
	RANGE:     "range",
	RETURN:    "return",

	SELECT: "select",
	STRUCT: "struct",

// TODO(mdempsky): Investigate replacing with switch statements or dense arrays.

var branchOps = [...]ir.Op{
	syntax.Break:       ir.OBREAK,
	syntax.Continue:    ir.OCONTINUE,
	syntax.Fallthrough: ir.OFALL,
	syntax.Goto:        ir.OGOTO,
}

var callOps = [...]ir.Op{
	syntax.Defer: ir.ODEFER,
	syntax.Go:    ir.OGO,

def run(playwright: Playwright) -> None:
    browser = playwright.chromium.launch(headless=False)
    context = browser.new_context(viewport={"width": 960, "height": 1080})
    page = context.new_page()
    page.goto("http://localhost:8000/docs")
    page.get_by_role("button", name="Item", exact=True).click()
    page.set_viewport_size({"width": 960, "height": 700})
    page.screenshot(