execute method
The iterable, nested function that evaluates the entire FHIRPath expression one object at a time
Implementation
@override
List execute(List results, Map<String, dynamic> passed) => [
results
.map((e) => e is num
? e
: throw FhirPathEvaluationException(
'sum() can only add numbers.',
operation: 'sum',
arguments: e,
collection: results))
.sum
];