[leetcode] 709. To Lower Case

题目：

Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase.

Example 1:

Input: "Hello"
Output: "hello"

Example 2:

Input: "here"
Output: "here"

Example 3:

Input: "LOVELY"
Output: "lovely"

代码：

class Solution {
    public String toLowerCase(String str) {
        return str.toLowerCase();
    }
}