package Ġorg . ny pl . simpl ified . books . controller . api Ċ Ċ /** Ċ Ġ* ĠAn Ġexception Ġindicating Ġthat Ġbook Ġrev oking Ġfailed Ġbecause Ġserver Ġreturned Ġan Ġun usable Ġfeed . Ċ Ġ*/ Ċ Ċ class ĠBook Re voke Exception Bad Feed Ġ: ĠBook Re voke Exception (" Un usable Ġfeed ") Ċ