code: @NonNull
      public ReplicatorConfiguration setAuthenticator(@NonNull Authenticator authenticator) {
          if (readonly) { throw new IllegalStateException("ReplicatorConfiguration is readonly mode."); }
          this.authenticator = authenticator;
          return getReplicatorConfiguration();
      }
docs: Sets the authenticator to authenticate with a remote target server.
  Currently there are two types of the authenticators,
  BasicAuthenticator and SessionAuthenticator, supported.
  
  @param authenticator The authenticator.
  @return The self object.