'Retrieve the simplified body structure of one or more messages
This command is allowed in the Selected state.
@type messages: C{MessageSet} or L{str}
@param messages: A message sequence set
@type uid: C{bool}
@param uid: Indicates whether the message sequence set is of message
numbers or of unique message IDs.
@rtype: C{Deferred}
@return: A deferred whose callback is invoked with a dict mapping
message numbers to body data, or whose errback is invoked
if there is an error.  The simplified body structure is the same
as the body structure, except that extension fields will never be
present.'

def fetchSimplifiedBody(self, messages, uid=0):

    return self._fetch(messages, useUID=uid, body=1)
