Version 2.0 (with breaking changes)

Added asynchronous methods, withSourcesAsync and cleanAsync.
All property accessors like .clean are now methods (e.g. .clean ()) for consistency reasons
.pretty now .asTable (opts?: { maxColumnWidths:? { callee, file, sourceLine } })
- Also, it does not call withSources automatically — you need to call it explicitly.
It is no longer extends Array due to non-working user subclassing with Babel ES5
- Use .items to access original array
No static methods and properties (except public .locationsEqual helper)
- .isThirdParty is now just an overrideable method
- .maxColumnWidths is an overrideable method + a configuration option passed to asTable () method