code: function (overlay) {
  
              var isInstance = overlay instanceof Overlay,
                  overlays = this.overlays,
                  n = overlays.length,
                  found = null,
                  o,
                  i;
  
              if (isInstance || typeof overlay == "string") {
                  for (i = n-1; i >= 0; i--) {
                      o = overlays[i];
                      if ((isInstance && (o === overlay)) || (o.id == overlay)) {
                          found = o;
                          break;
                      }
                  }
              }
  
              return found;
          }
docs: Attempts to locate an Overlay by instance or ID.
  @method find
  @param {Overlay} overlay  An Overlay to locate within the manager
  @param {String} overlay  An Overlay id to locate within the manager
  @return {Overlay} The requested Overlay, if found, or null if it
  cannot be located.