def identifier_header_name
      if SimpleTokenAuthentication.header_names["#{name_underscore}".to_sym].presence \
        && identifier_header_name = SimpleTokenAuthentication.header_names["#{name_underscore}".to_sym][identifier]
        identifier_header_name
      else
        "X-#{name_underscore.camelize}-#{identifier.to_s.camelize}"
      end
    end
def identifier_header_name
      if SimpleTokenAuthentication.header_names["#{name_underscore}".to_sym].presence \
        && identifier_header_name = SimpleTokenAuthentication.header_names["#{name_underscore}".to_sym][identifier]
        identifier_header_name
      else
        "X-#{name_underscore.camelize}-#{identifier.to_s.camelize}"
      end
    end
Private: Return the name of the header to watch for the email param