function findIndexOf(arr, cb) {
	  var idx = -1;
	  arr.some(function (d, i) {
	    if (cb(d, i)) {
	      idx = i;
	      return true;
	    }
	  });
	  return idx;
	}
Proper state managment for containers and the modals in those containers.

@internal Used by the Modal to ensure proper styling of containers.