value property
value
The match value may be either a code defined by the system, or a
string value, which is a regex match on the literal string of the property
value (if the filter represents a property defined in CodeSystem) or of
the system filter value (if the filter represents a filter defined in
CodeSystem) when the operation is 'regex', or one of the values (true and
false), when the operation is 'exists'.
Implementation
String? get value => throw _privateConstructorUsedError;