When an input of an executable map evaluates to NONE
The evaluation of a map referenced in an expression differs from the evaluation of that map when it is executed as a functional map and the evaluation of a function because of how the NONE is treated.
The evaluation of a map used as a function is different from the evaluation of that map when it is run as an executable map. When a map is run as an executable, if any input card data object has no content, the map will still run. This is not true when that map is referenced as a function. If any input argument of a functional map evaluates to "none", the map will not evaluate.