code: function repeat(coll, n) {
    if (arguments.length === 1) {
      n = coll;
      return function(xform) {
        return new Repeat(n, xform);
      };
    }
    return seq(coll, repeat(n));
  }
docs: Returns a new collection containing elements of the given
  collection, each repeated n times. Returns a transducer if a
  collection is not provided.