def pull_credentials(params)
      (@credentials || []).map do |credential|
        params.delete(credential) || params.delete(credential.to_s)
      end.compact
    end
def pull_credentials(params)
      (@credentials || []).map do |credential|
        params.delete(credential) || params.delete(credential.to_s)
      end.compact
    end
Private: Separate the credentials for authentication from the other
 request parameters.