Improve code quality

[gladwintan]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/main/java/seedu/address/ui/PersonCard.java	0.00%	1 Missing ⚠️

Files with missing lines	Coverage Δ	Complexity Δ
...logic/commands/MarkAttendanceByStudentCommand.java	86.36% <ø> (ø)	18.00 <0.00> (ø)
...c/parser/MarkAttendanceByStudentCommandParser.java	100.00% <ø> (ø)	4.00 <0.00> (ø)
.../parser/MarkAttendanceByTutorialCommandParser.java	92.85% <ø> (ø)	4.00 <0.00> (ø)
...in/java/seedu/address/logic/parser/ParserUtil.java	68.42% <ø> (ø)	26.00 <0.00> (ø)
...in/java/seedu/address/model/person/Attendance.java	75.00% <ø> (ø)	9.00 <0.00> (ø)
src/main/java/seedu/address/ui/AttendanceCard.java	0.00% <ø> (ø)	0.00 <0.00> (ø)
...ain/java/seedu/address/ui/AttendanceContainer.java	0.00% <ø> (ø)	0.00 <0.00> (ø)
src/main/java/seedu/address/ui/PaymentCard.java	0.00% <ø> (ø)	0.00 <0.00> (ø)
...rc/main/java/seedu/address/ui/PersonListPanel.java	0.00% <ø> (ø)	0.00 <0.00> (ø)
src/main/java/seedu/address/ui/PersonCard.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)

... and 1 file with indirect coverage changes

[Slipperybara]

LGTM