'L{IMAP4Client.fetchBody} sends the I{FETCH BODY} command and returns a
L{Deferred} which fires with a C{dict} mapping message sequence numbers
to C{dict}s mapping C{\'RFC822.TEXT\'} to that message\'s body as given in
the server\'s response.'

def test_fetchBody(self):

    d = self.client.fetchBody('3')
    self.assertEqual(self.transport.value(), '0001    FETCH    3    (RFC822.TEXT)\r\n')
    self.client.lineReceived('*    3    FETCH    (RFC822.TEXT    "Message    text")')
    self.client.lineReceived('0001    OK    FETCH    completed')
    self.assertEqual(self._extractDeferredResult(d), {3: {'RFC822.TEXT': 'Message    text'}})
