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: cache.go
    path of file: ./repos/sliver/implant/vendor/github.com/tetratelabs/wazero
    
    the code of the file until where you have to start completion: package wazero

import (
	"context"
	"errors"
	"fmt"
	"os"
	"path"
	"path/filepath"
	goruntime "runtime"
	"sync"

	"github.com/tetratelabs/wazero/api"
	"github.com/tetratelabs/wazero/internal/filecache"
	"github.com/tetra
    
func (c *cache) ensuresFileCache(dir string, wazeroVersion string) error {
	// Resolve a potentially relative directory into an absolute one.
	var err error
	dir, err = filepath.Abs(dir)
	if err != nil {
		return err
	}

	// Ensure the user-supplied directory.
	if err = mkdir(dir); err != nil {
		return err
	}

	// Create a version-specific directory to avoid conflicts.
	dirname := path.Join(dir, "wazero-"+wazeroVersion+"-"+goruntime.GOARCH+"-"+goruntime.GOOS)
	if err = mkdir(dirname); err != nil {
		return err
	}

	c.fileCache = filecache.New(dirname)
	return nil
}