Fixed metadata serialization
Merge branch '2.0' into 2.1

* 2.0:
  Fixed metadata serialization
[Validator] fixed metadata serialization
Merge branch '2.1' into 2.2

* 2.1:
  [Validator] fixed metadata serialization
  Fixed metadata serialization
Merge branch '2.2' into 2.3

* 2.2:
  [Validator] fixed metadata serialization
  Fixed metadata serialization