@Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }

            AnError anError = (AnError) o;

            if (!message.equals(anError.message)) {
                return false;
            }

            return true;
        }
This error has a message and an equals() implementation as to be able
to match it against the serialized version of itself.
tika-parsers/tika-parsers-standard/tika-parsers-standard-package/src/test/java/org/apache/tika/parser/fork/ForkParserIntegrationTest.java