Approver {abstract}
#successor :Approver#name :String
+Approver(String name)+setSuccessor(Approver successor) :void+porcessRequest(PurchaseRequest request) :void
PurchaseRequest
-amount:double-number:int-purpose:String
VicePresident
+VicePresident(String name)+processRequest(PurchaseRequest request) :void
Congress
+Congress(String name)+processRequest(PurchaseRequest request) :void
President
+President(String name)+processRequest(PurchaseRequest request) :void
Author : 汪锴Date: 20160516Number: 2013011404
Director
+Director(String name)+processRequest(PurchaseRequest request) :void
