Refactor all the things

shapes.js

@@ -9,6 +9,12 @@ class Rectangle {
   }
 }
 
+class CircleGetsTheSquare {
+  constructor(circumference, radius) {
+    this.circumference = circumference
+    this.radius = radius
+  }
+
 class Square extends Rectangle {
   constructor(x) {
     super(x, x)

underscore.js

@@ -14,6 +14,29 @@ _.min = function(obj, iteratee, context) {
 				result = value;
 			}
 		}
+		_.sortBy = function(obj, iteratee, context) {
+			var index = 0;
+			iteratee = cb(iteratee, context);
+			return _.pluck(
+				_.map(obj, function(value, key, list) {
+					return {
+						value: value,
+						index: index++,
+						criteria: iteratee(value, key, list)
+					};
+				}).sort(function(left, right) {
+					var a = left.criteria;
+					var b = right.criteria;
+					if (a !== b) {
+						if (a > b || a === void 0) return 1;
+						if (a < b || b === void 0) return -1;
+					}
+					return left.index - right.index;
+				}),
+				"value"
+			);
+		};
+
 	} else {
 		iteratee = cb(iteratee, context);
 		_.each(obj, function(v, index, list) {
@@ -27,6 +50,24 @@ _.min = function(obj, iteratee, context) {
 	return result;
 };
 
+_.sampleThis = function(obj, n, guard) {
+	if (n == null || guard) {
+		if (!isArrayLike(obj)) obj = _.values(obj);
+		return obj[_.random(obj.length - 1)];
+	}
+	var sample = isArrayLike(obj) ? _.clone(obj) : _.values(obj);
+	var length = getLength(sample);
+	n = Math.max(Math.min(n, length), 0);
+	var last = length - 1;
+	for (var index = 0; index < n; index++) {
+		var rand = _.random(index, last);
+		var temp = sample[index];
+		sample[index] = sample[rand];
+		sample[rand] = temp;
+	}
+	return sample.slice(0, n);
+};
+
 _.shuffle = function(obj) {
 	return _.sample(obj, Infinity);
 };