StackGenVis/frontend/node_modules/protocol-buffers-schema/example.proto

// example file

message Test {
  map<string, string> data = 1;
  required string hello = 2;
  oneof test {
    uint32 age = 3;
    uint32 year = 4;
  }
  message Nested {
    optional bytes thing = 1;
  }
}