setHeaders method
Saves headers for later use
Implementation
void setHeaders(Map<String, String> headers) {
for (final headerToMap in _headersToMap) {
final value = headers[headerToMap];
if (value == null) continue;
_headers[headerToMap] = value;
}
/// Print new headers
assert((() {
if (_debug) print(jsonEncode(_headers));
return true;
})());
}