printStringMapMap method
print Map<String, Map<String, String>> map nicely
Implementation
void printStringMapMap(Map<String, Map<String, String>> _map) {
int _length = _map.length;
print(':D-T: #printStringMapMap : length: $_length ');
List<String> nameL = _map.keys.toList();
for (var x = 0; x < _length; x++) {
String name = nameL[x];
// howTo NULL int num : int _l OR: ready value int _l = 0;
// NO-toInt int _l = _map[name].length.toInt();
int _l = 0;
// howTo NULL Map-field-length noComprendo
// OK with ! and toInt()
_l = _map[name]!.length.toInt();
print('\n mapName: $name -------------- length: $_l -----------------');
// DO:9 Return map in sort-order: value.
_map[name]!.forEach((k, v) => print('$k, $v'));
}
}