sun/net/www/http/HttpClient/IsAvailable.java fails intermittently

This happened once on Solaris X64

Please refer to the test output:
----------System.err:(12/713)----------
java.lang.RuntimeException: connection should be available
at IsAvailable.main(IsAvailable.java:55)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:538)
at com.sun.javatest.regtest.agent.MainActionHelper$SameVMRunnable.run(MainActionHelper.java:230)
at java.base/java.lang.Thread.run(Thread.java:844)