package Ġnet . j anc z ar . kotlin rx . data . api Ċ Ċ import Ġio . reactivex . Single Ċ import Ġnet . j anc z ar . kotlin rx . data . model . Hello Response Ċ import Ġretrofit 2 . http . GET ĊĊ Ċ interface ĠHello API Ġ{ ĊĊĠĠĠ Ġ@ GET (" hello ") ĊĠĠĠ Ġfun Ġsay Hello (): ĠSingle < Hello Response > Ċ Ċ }