Description: The replaceNull function returns the argument if the Subject is null. Otherwise, returns the Subject.

Subject Type: Any

Arguments:

Return Type: Type of Subject if Subject is not null; else, type of Argument

Examples: If the attribute "filename" has the value "a brand new filename.txt" and the attribute "hello" does not exist, then the Expression ${filename:replaceNull('abc')} will return "a brand new filename.txt", while ${hello:replaceNull('abc')} will return "abc".