Given two strings `s` and `t`, return `true` if `t` is an anagram of `s`, and `false` otherwise.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Example 1:

    Input: s = "anagram", t = "nagaram"
    Output: true

Example 2:

    Input: s = "rat", t = "car"
    Output: false

Constraints:

- `1 <= s.length, t.length <= 5 * 104`
- `s` and `t` consist of lowercase English letters.

Follow up: What if the inputs contain Unicode characters? How would you adapt your solution to such a case?