* Implement table name extraction tests.
* Address comments.
* Fix tests and reimplement the token processing.
* Exclude aliases.
* Clean up print statements and code.
* Reverse select test.
* Fix failing test.
* Test JOINs
* refactore as a class
* Check for permissions in SQL Lab.
* Implement permissions check for the datasources in sql_lab
* Address comments.
Bogdan