I am working on NIFI-12756 to better understand when NIFI expressions can throw exceptions. I have an attribute which is a negative number and I thought calling toInstant would have thrown an org.apache.nifi.attribute.expression.language.exception.AttributeExpressionLanguageException but instead it evaluated to 1925-07-10T09:28:41.358Z. I tried using toInstant as some of the unit tests (in nifi/nifi-commons/nifi-expression language/src/test/java/org/apache/nifi/attribute/expression/language/TestQuery.java) use it without any arguments although the documentation <https://nifi.apache.org/docs/nifi-docs/html/expression-language-guide.html#toinstant> details using it with arguments format and timeZone. Can someone please clarify the following:
1. Does the documentation need to be changed to indicate the arguments are not required? 2. Why does toInstant evaluate with a negative number and not throw an exception?
