private static void isTrue(boolean expression, String message) {
        if (!expression) {
            throw new IllegalArgumentException(message);
        }
    }
Find the requested number of available ports for this {@code SocketType},
each randomly selected from the range [{@code minPort}, {@code maxPort}].
@param numRequested the number of available ports to find
@param minPort the minimum port number
@param maxPort the maximum port number
@return a sorted set of available port numbers for this socket type
@throws IllegalStateException if the requested number of available ports could not be found
agent-module/plugins-test-module/testcase/src/main/java/com/navercorp/pinpoint/testcase/util/SocketUtils.java