code: protected CougarException handleResponseWritingIOException(Exception e, Class resultClass) {
          String errorMessage = "Exception writing "+ resultClass.getCanonicalName() +" to http stream";
          IOException ioe = getIOException(e);
          if (ioe == null) {
              CougarException ce;
              if (e instanceof CougarException) {
                  ce = (CougarException)e;
              } else {
                  ce = new CougarFrameworkException(errorMessage, e);
              }
              return ce;
          }
  
  		//We arrive here when the output pipe is broken. Broken network connections are not
  		//really exceptional and should not be reported by dumping the stack trace.
  		//Instead a summary debug level log message with some relevant info
          incrementIoErrorsEncountered();
  		LOGGER.debug(
  				"Failed to marshall object of class {} to the output channel. Exception ({}) message is: {}",
  				resultClass.getCanonicalName(),
  				e.getClass().getCanonicalName(),
  				e.getMessage()
  		);
  		return new CougarServiceException(ServerFaultCode.OutputChannelClosedCantWrite, errorMessage, e);
  	}
docs: If an exception is received while writing a response to the client, it might be
  because the that client has closed their connection. If so, the problem should be ignored.