Fix UG accordings to the suggestions

[Elinengu]

• Closes #296
• Closes #250
• Closes #252
• Closes #298
• Closes #270
• Closes #272
• Closes #302
• Closes #303
• Closes #259

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

[MAOXIONGKAI]

This PR also closes #249