isEmpty
Description: The isEmpty function returns true if the Subject is null, does not contain any characters or contains only white-space (new line, carriage return, space, tab), false otherwise.
Subject Type: String
Arguments: No arguments
Return Type: Boolean
Examples: ${filename:isEmpty()} returns true if the "filename" attribute does not exist or contains only white space. ${literal(" "):isEmpty()} returns true as well as ${literal(""):isEmpty()}.
