Revert "Various clean-ups and null-safety improvements. (#140)" (#152)

This reverts commit 05b9553c81b0168e7665d47730977ca289334a69.

Since this has not been published or rolled through to the SDK or
Flutter we will hold it back to reduce risk.
8 files changed
tree: 29b6f625d6652971c884c37e50e73781026273bd
  1. .github/
  2. lib/
  3. test/
  4. .gitignore
  5. analysis_options.yaml
  6. AUTHORS
  7. CHANGELOG.md
  8. CONTRIBUTING.md
  9. LICENSE
  10. pubspec.yaml
  11. README.md
README.md

Contains utility classes in the style of dart:async to work with asynchronous computations.