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: ksuid_test.go
    path of file: ./repos/ksuid
    
    the code of the file until where you have to start completion: package ksuid

import (
	"bytes"
	"encoding/json"
	"flag
    
func testPrevNext(t *testing.T, id, prev, next KSUID) {
	id1 := id.Prev()
	id2 := id.Next()

	if id1 != prev {
		t.Error("previous id of the nil KSUID is wrong:", id1, "!=", prev)
	}

	if id2 != next {
		t.Error("next id of the nil KSUID is wrong:", id2, "!=", next)
	}
}