code: function(set) {
              if (!set || !set.length) return;
              var i = 1,
                  l = set.length,
                  current,
                  master = set[0],
                  tmp;
              master = [
                  master._x,
                  master._y,
                  master._x + master._w,
                  master._y + master._h
              ];
              while (i < l) {
                  current = set[i];
                  tmp = [
                      current._x,
                      current._y,
                      current._x + current._w,
                      current._y + current._h
                  ];
                  if (tmp[0] < master[0]) master[0] = tmp[0];
                  if (tmp[1] < master[1]) master[1] = tmp[1];
                  if (tmp[2] > master[2]) master[2] = tmp[2];
                  if (tmp[3] > master[3]) master[3] = tmp[3];
                  i++;
              }
              tmp = master;
              master = {
                  _x: tmp[0],
                  _y: tmp[1],
                  _w: tmp[2] - tmp[0],
                  _h: tmp[3] - tmp[1]
              };
  
              return master;
          }
docs: @
  #Crafty.rectManager.boundingRect
  @comp Crafty.rectManager
  @kind Method
  
  @sign public Crafty.rectManager.boundingRect(set)
  @param set - An array of rectangles
  
  - Calculate the common bounding rect of multiple canvas entities.
  - Returns coords