addHeader method
Insert a header of the given name and value into the last position of the header array.
Implementation
void addHeader(String name, dynamic value) {
Map<String, dynamic> header = <String, dynamic>{'raw': value};
name = utils.headerize(name);
if (headers![name] != null) {
headers![name].add(header);
} else {
headers![name] = <dynamic>[header];
}
}