def get_master(exchange_id, format=u"Default"):
  """
    Requests a calendar item from the store.

    exchange_id is the id for this event in the Exchange store.

    format controls how much data you get back from Exchange. Full docs are here, but acceptible values
    are IdOnly, Default, and AllProperties.

    http://msdn.microsoft.com/en-us/library/aa564509(v=exchg.140).aspx

    <m:GetItem  xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages"
            xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
      <m:ItemShape>
          <t:BaseShape>{format}</t:BaseShape>
      </m:ItemShape>
      <m:ItemIds>
          <t:RecurringMasterItemId OccurrenceId="{exchange_id}"/>
      </m:ItemIds>
  </m:GetItem>

  """

  root = M.GetItem(
    M.ItemShape(
      T.BaseShape(format)
    ),
    M.ItemIds(
      T.RecurringMasterItemId(OccurrenceId=exchange_id)
    )
  )
  return root
Requests a calendar item from the store.

    exchange_id is the id for this event in the Exchange store.

    format controls how much data you get back from Exchange. Full docs are here, but acceptible values
    are IdOnly, Default, and AllProperties.

    http://msdn.microsoft.com/en-us/library/aa564509(v=exchg.140).aspx

    <m:GetItem  xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages"
            xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
      <m:ItemShape>
          <t:BaseShape>{format}</t:BaseShape>
      </m:ItemShape>
      <m:ItemIds>
          <t:RecurringMasterItemId OccurrenceId="{exchange_id}"/>
      </m:ItemIds>
  </m:GetItem>