The request message for the operation clear(). The response message for the operation clear(). The request message for the operation getSize(). The response message for the operation getSize(). The request message for the operation getRecentCalls(). The response message for the operation getRecentCalls(). The request message for the operation addCall(). The response message for the operation addCall(). Clear recent calls list. Get size of recent calls list. Get recent calls list. Add a call to recent calls list.