public static int findAvailableUdpPort() {
        return findAvailableUdpPort(PORT_RANGE_MIN);
    }
Find an available UDP port randomly selected from the range
[{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
@return an available UDP port number
@throws IllegalStateException if no available port could be found
agent-module/plugins-test-module/testcase/src/main/java/com/navercorp/pinpoint/testcase/util/SocketUtils.java