Nested if else (if else ladder)
https://medium.com/@arnab.sen44/how-i-refactored-a-nested-if-else-validation-using-a-design-pattern-ce287c32851d
https://medium.com/swlh/5-ways-to-replace-if-else-statements-857c0ff19357

Guard clause
https://refactoring.guru/ko/replace-nested-conditional-with-guard-clauses
https://deviq.com/design-patterns/guard-clause
https://refactoring.com/catalog/replaceNestedConditionalWithGuardClauses.html