Unnecessary return statement (?)

[gentzeng]

In Line 23 of main.ts, a return statement is applied on this.handleCheckboxReplacement, while in line 32, it isn't. Line 23 is the only place in the entire main.ts, where a return is applied on a non-returning function.

I suggest using void return types for all for this.handleCheckboxReplacement and all other non returning functions, since the compile will throw an error.