feature: add function

[liwuhen]

Description

Related Issue

Type of Change

The [x] notation can be used to indicate compliance with the selection.

• Examples / docs / dependencies update.
• Bug fix.
• Improvement (non-breaking change which improves an existing feature).
• New feature (non-breaking change which adds functionality).
• Security fix.

Checklist

The [x] notation can be used to indicate compliance with the selection.

• My code follows the style guidelines of this project.
• I have reviewed the CODE_OF_CONDUCT.md document.
• I have consulted the CONTRIBUTING.md guide.
• I have applied the code style updates using make codestyle.
• I have authored tests for any new methods and classes.
• I have documented all utilized methods and classes in Google style docstrings.
• New and existing unit tests pass locally with my changes