Refactoring AddLine with AppendWhen
Refactoring AddLine with AppendWhen

kshanafelt/commandline,Thilas/commandline,Ehryk/commandline,nausley/commandline,anthonylangsworth/commandline,huoxudong125/commandline,Emergensys/commandline,rmboggs/commandline,Emergensys/commandline,Ehryk/commandline,anthonylangsworth/commandline,kshanafelt/commandline,Thilas/commandline,rmboggs/commandline,nausley/commandline,huoxudong125/commandline