Api refactoring
Api refactoring


Former-commit-id: 7788a4c7f50b0b051101cb240b669925990ddc04
alekseysidorov/exonum,alekseysidorov/exonum,exonum/exonum,exonum/exonum,alekseysidorov/exonum,exonum/exonum,exonum/exonum,alekseysidorov/exonum