set method
Sets a header. The header named name
will have all its values
cleared before the value value
is added as its value.
Implementation
void set(String name, dynamic value) {
if (value == null) return;
name = name.trim().toLowerCase();
if (value is List) {
_map[name] = value.map<String>((e) => e.toString()).toList();
} else {
_map[name] = ['$value'.trim()];
}
}