* Add tests for serializing connected blocks
* Add serialization of child blocks
* Add tests for not serializing children
* Add options for not serializing children
* Fix types
* Change addNextBlocks to default to true
* Cleanup
* Fix types
* Add tests for saving extra state
* Add serializing extra state
* Fix backwards compatibility
* Switch to other function declarations
* Handle null returns from hooks
* Remove backwards compatibility
* Remove XML require, and fix type
* Fix JSDoc formatting
* Add basic attribute tests
* Add basic block serialization
* Add more attribute tests
* Change save to use options dictionary
* Add obeying save options
* Add test for data attribute
* Add saving data tag
* Move to ES6 syntax
* Fixup move to es6 syntax
* Declare module
* Format and lint
* Add docs
* Add returning null on insertion markers
* Fixup for move to module
* Switch to other function declarations
* Cleanup for finalized style
* Fix lint and types
* Export State def
* Switch disabled=true to enabled=false