Error: Assertion failed: Tandem was required but not supplied
at window.assertions.assertFunction (https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/assert/js/assert.js:21:13)
at Tandem.addInstance (https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/tandem/js/Tandem.js?bust=1491337897649:86:21)
at BucketFront.setTandem (https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/scenery/js/nodes/Node.js?bust=1491337897649:3467:22)
at BucketFront.set tandem [as tandem] (https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/scenery/js/nodes/Node.js?bust=1491337897649:3472:32)
at https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/scenery/js/nodes/Node.js?bust=1491337897649:4763:25
at u (https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/sherpa/lib/lodash-4.17.4.min.js?bust=1491337897649:5:432)
at Function.ru (https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/sherpa/lib/lodash-4.17.4.min.js?bust=1491337897649:67:656)
at BucketFront.mutate (https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/scenery/js/nodes/Node.js?bust=1491337897649:4750:9)
at new BucketFront (https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/scenery-phet/js/bucket/BucketFront.js?bust=1491337897649:66:10)
at https://bayes.colorado.edu/continuous-testing/snapshot-1491336896246/shred/js/view/InteractiveSchematicAtom.js?bust=1491337897649:131:25
Approximately 4/4/2017, 2:14:56 PM