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: 342. Power of Four.go
    path of file: ./repos/LeetCode-Go/leetcode/0342.Power-of-Four
    
    the code of the file until where you have to start completion: package leetcode

// 解法一 数论
func isPowerOfFour(num int) bool {
	return num > 0 && (num&
    
func isPowerOfFour1(num int) bool {
	for num >= 4 {
		if num%4 == 0 {
			num = num / 4
		} else {
			return false
		}
	}
	return num == 1
}