Order

- Refactor unique object tree walking. (4340a6f)
- Update legacy tests. (ee3215a)
- Do not accept None as shift name. (fb0ee7d)
- Streamline existing API docs. (2b2b695, 3671a13)

Features & updates

- Rename selection_mode to str_selection_mode. (934e065)
- Modernize docs (523dd78, dbbde2a, 89b790e)


Fixes

- Remove duplicates in get_{leaf,root}_ tree methods. (2af864b)
- Fix category copy_shallow (cda3833)

Features

- Add copy_shallow to all objects. (376f08f)
- - Add discrete_{x,y} flags to variables. (2b97da5)
- Refactor docs. (343210c)

Fixes

- Fix variable get_full_y_title. (31dcbc1)

Breaking changes

- Rename log_{x,y} and discrete_{x,y} attributes of Variable. (ead2d20)

Features

- Allow colors in ColorMixin to be nullable. (2db988b)
- Remove constraint on number of x_labels for Variable. (c42b906)
- Add support for secondary and tertiary color in ColorMixin. (2cb038f)
- Allow empty data source in DataSourceMixin. (0ae6fbd)
- Update into notebook. (0b8db6b)

Fixes

- Fix test requirements. (ae0da66, f96b6de)

Breaking updates

- Drop contexts and instance caching. (fd061db)
- Refactor unique object handling (a3cfc4d)
- Refactor copy behavior. (a57ee9f)

Fixes and minor changes

- Update examples and notebook. (244c243)
- Update code style. (3ef6c35)
- Fix pypi publish action. (394e7a0)

Features

- Allow selections to be callables. (9256a89)