encode method
Implementation
void encode(KeyedArchive object) {
super.encode(object);
if (version == null || info == null || paths == null) {
throw ArgumentError(
"APIDocument must have non-null values for: 'version', 'info', 'paths'.");
}
object.encode("openapi", version);
object.encodeObject("info", info);
object.encodeObjects("servers", servers);
object.encodeObjectMap("paths", paths);
object.encodeObject("components", components);
object.encode("security", security);
object.encodeObjects("tags", tags);
}