generateConstants method
Writes a Dart constant containing the JSON for the EnumProtoDescriptor.
Implementation
void generateConstants(IndentingWriter out) {
final name = getJsonConstant(fileGen!);
final json = _descriptor.writeToJsonMap();
out.println('@$coreImportPrefix.Deprecated'
'(\'Use ${toplevelParent!.binaryDescriptorName} instead\')');
out.print('const $name = ');
writeJsonConst(out, json);
out.println(';');
out.println();
}