Generate a text based on the cache.
Selects a random word in the cache as the first (resp. last) word,
and continues forward (resp. backward) using the cache in the
right direction, until it selects a message end from the cache
or that the max_size is met.
The seed may be a string or a 2-tuple of strings.
Returns a view on the 2-tuples of words in the corpus.
Useful if you want to match them against a new message.
decorator for extracters that handle decoding messages with the
right charset (if chardet or charade is installed) or as utf8