Bug in Node js

If space don't have static objects, in 2565 lines in cp.js file
`if(this.root) subtreeQuery(this.root, bb, func);`
`this` - global node js object, and it have `root` property. And the condition is true, although `this` don't `cp.BBTree`. Additional check on the `this instanceof cp.BBTree` solves the problem.

Inspect cp.js around line 2565 and reproduce the query when no static objects exist. Verify the receiver is the global Node.js object rather than a cp.BBTree, and consider the issue's suggested instance check; done means that case no longer enters the subtree query while valid cp.BBTree queries still work.

Written by the indexing model from the issue text.