Imported current version from 04-JUnit.
Used Storeable, added serialization skeleton, refactored Command-s.
Updated tests (yet non-functional).
It actually somewhat works now.
Made a unified way to execute commands.
Now works with spaces in parentheses and brackets.
Nullability support, various fixes.
Updated tests to work on structured version.
null-value tests.
Implemented methods not mentioned in task statement.
Updated parsers.
Unused variable.
Method reference to stop Idea from complaining.
Different expect syntax to stop Travis from complaining.
Final codestyle fix.
Magic.
More magic.
Check for empty/null arguments.
Lol. Fixed.
(More) proper testing directory declaration, cleanup after tests.