old_contents: "use strict";
  
  function sane(n) {
      var attempt = Number(n || 0).valueOf();
      if(isNaN(attempt)) throw "Invalid number " + n;
  
      return attempt;
  }
  function Vector(x, y) {
      this.x = sane(x);
      this.y = sane(y);
  }
  Vector.prototype.toString = function() { return "(" + this.x + ", " + this.y + ")"; };
  Vector.prototype.add = function(other) {
      return new Vector(this.x + other.x, this.y + other.y);
  }
  Vector.prototype.subtract = function(other) {
      return new Vector(this.x - other.x, this.y - other.y);
  }
  Vector.prototype.scale = function(scalar) {
      return new Vector(this.x * scalar, this.y * scalar);
  }
  
  var Point = Vector; // displacement from Origin
  var Size = Vector; // (width, height)
  
  function Body(center, size, weight, velocity, orientation) {
      this.center = center; // Point
      this.size = size; // Size
      this.weight = weight; // Number
      this.velocity = velocity; // Vector
      this.orientation = orientation; // Vector
  }
  
new_contents: "use strict";
  
  function sane(n) {
      var attempt = Number(n || 0).valueOf();
      if(isNaN(attempt)) throw "Invalid number " + n;
  
      return attempt;
  }
  function Vector(x, y) {
      this.x = sane(x);
      this.y = sane(y);
  }
  Vector.prototype.toString = function() { return "(" + this.x + ", " + this.y + ")"; };
  Vector.prototype.add = function(other) {
      return new Vector(this.x + other.x, this.y + other.y);
  }
  Vector.prototype.subtract = function(other) {
      return new Vector(this.x - other.x, this.y - other.y);
  }
  Vector.prototype.scale = function(scalar) {
      return new Vector(this.x * scalar, this.y * scalar);
  }
  Vector.prototype.magnitude = function() {
      return Math.sqrt(this.x*this.x + this.y*this.y);
  }
  
  var Point = Vector; // displacement from Origin
  var Size = Vector; // (width, height)
  
  function Body(center, size, weight, velocity, orientation) {
      this.center = center; // Point
      this.size = size; // Size
      this.weight = weight; // Number
      this.velocity = velocity; // Vector
      this.orientation = orientation; // Vector
  }
  
subject: add Vector::magnitude