Feeding RecordArray from ember-data causes an error

First of all I wish to thank you for the good work.

I'm using Ember 3.0.0 with git's master of ember-table

I'm setting up a new table whose rows are fed from an ember-data RecordArray and I'm getting this javascript error, even when the RecordArray is actually empty:

collapse-tree.js:356 Uncaught TypeError: Ember.get(...).some is not a function
    at CollapseTreeNode.get isLeaf (collapse-tree.js:356)
    at ComputedProperty.get (ember-metal.js:2536)
    at Object._get [as get] (ember-metal.js:1358)
    at CollapseTreeNode.get length (collapse-tree.js:448)
    at ComputedProperty.get (ember-metal.js:2536)
    at _get (ember-metal.js:1358)
    at _getPath (ember-metal.js:1405)
    at Object._get [as get] (ember-metal.js:1390)
    at CollapseTree.get length (collapse-tree.js:626)
    at ComputedProperty.get (ember-metal.js:2536)

Explicitly disabling tree with enableTree=false property works around the problem.

Start at collapse-tree.js:356, where the stack trace reports the failure while handling a RecordArray, and reproduce it with Ember 3.0.0 and tree support enabled. Compare this with the enableTree=false workaround; done means a table fed by an ember-data RecordArray, including an empty one, no longer raises the reported error.