Description: Converts a URL-friendly version of the Subject into a human-readable form.

Subject Type: String

Arguments: No arguments

Return Type: String

Examples: If we have a URL-Encoded attribute named "url" with the value "https://nifi.apache.org/some%20value%20with%20spaces", then the Expression ${url:urlDecode()} will return "https://nifi.apache.org/some value with spaces".