You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: context_x.go
    path of file: ./repos/darktile/vendor/github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl
    
    the code of the file until where you have to start completion: // Copyright 2020 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you
    
func isPBOAvailable() bool {
	pboAvailableOnce.Do(func() {
		// This must be called after GL context is created.
		str := gl.RendererDeviceString()
		tokens := strings.Split(str, " ")
		if len(tokens) == 0 {
			return
		}
		// Raspbery Pi 4 has an issue around PBO (#1208).
		if tokens[0] == "V3D" {
			pboAvailable = false
		}
	})
	return pboAvailable
}