code: @Override
      public UnexpectedExceptionInformation getUnexpectedException(int code) {
          if (exceptionMapping == null) {
              exceptionMapping = processUnexpectedResponseExceptionTypes();
          }
  
          return exceptionMapping.getOrDefault(code, defaultException);
      }
docs: Get the {@link UnexpectedExceptionInformation} that will be used to generate a RestException if the HTTP response status
  code is not one of the expected status codes.
  
  If an UnexpectedExceptionInformation is not found for the status code the default UnexpectedExceptionInformation will be returned.
  
  @param code Exception HTTP status code return from a REST API.
  @return the UnexpectedExceptionInformation to generate an exception to throw or return.