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: any_number.go
    path of file: ./repos/hubble-ui/backend/vendor/github.com/json-iterator/go
    
    the code of the file until where you have to start completion: package jsoniter

import (
	"io"
	"unsafe"
)

type numberLazyAny struct {
	baseAny
	cfg *frozenConfig
	buf []byte
	err er
    
func (any *numberLazyAny) ToInt64() int64 {
	iter := any.cfg.BorrowIterator(any.buf)
	defer any.cfg.ReturnIterator(iter)
	val := iter.ReadInt64()
	if iter.Error != nil && iter.Error != io.EOF {
		any.err = iter.Error
	}
	return val
}