in lib/src/hitmap.dart [238:255]
void mergeHitmaps(
Map<String, Map<int, int>> newMap, Map<String, Map<int, int>> result) {
newMap.forEach((file, v) {
final fileResult = result[file];
if (fileResult != null) {
v.forEach((line, count) {
final lineFileResult = fileResult[line];
if (lineFileResult == null) {
fileResult[line] = count;
} else {
fileResult[line] = lineFileResult + count;
}
});
} else {
result[file] = v;
}
});
}