package Ġit . xp ug . mil ano . p act consumer . domain . port Ċ Ċ import Ġit . xp ug . mil ano . p act consumer . domain . model . Book Ċ Ċ interface ĠBook Service Ġ{ ĊĠĠĠ Ġfun Ġlist All (): ĠList < Book > ĊĠĠĠ Ġfun Ġget ById ( id : ĠInt ): ĠBook ? ĊĠĠĠ Ġfun Ġstore ( book : ĠBook ) Ċ } Ċ Ċ class ĠBook Store Exception Ġ: ĠRuntimeException ()