class Doorkeeper::OAuth::AuthorizationCodeRequest

def before_successful_response
  grant.transaction do
    grant.lock!
    raise Errors::InvalidGrantReuse if grant.revoked?
    grant.revoke
    find_or_create_access_token(grant.application,
                                grant.resource_owner_id,
                                grant.scopes,
                                server)
  end
  super
end