public boolean isAnagram(String s1, String s2) {
		// remove whitespace
		s1 = filterString(s1);
		s2 = filterString(s2);
		if (s1.length() != s2.length()) {
			return false;
		} else {
			Map<Integer> s1Map = new Map<>();
			Map<Integer> s2Map = new Map<>();

			s1Map.insert(s1);
			s2Map.insert(s2);

			boolean match = true;
			for (int i = 0; i < s1.length(); i++) {
				Character c = s1.charAt(i);
				if (s1Map.getFrequency(c) != s2Map.getFrequency(c)) {
					match = false;
				}
			}
			return match;
		}
	}