def resource_node(element, resources):
  """
  Helper function to generate a person/conference room node from an email address

  <t:OptionalAttendees>
    <t:Attendee>
        <t:Mailbox>
            <t:EmailAddress>{{ attendee_email }}</t:EmailAddress>
        </t:Mailbox>
    </t:Attendee>
  </t:OptionalAttendees>
  """

  for attendee in resources:
    element.append(
      T.Attendee(
        T.Mailbox(
          T.EmailAddress(attendee.email)
        )
      )
    )

  return element