'Extends the model with the given list of documents.'

def extend(self, documents):

    documents = list(documents)
    for (i, document) in enumerate(documents):
        if (not isinstance(document, Document)):
            documents[i] = Document(document)
        if (document.name is not None):
            self._index[document.name] = document
        document._model = self
    list.extend(self.documents, documents)
    if (self._weight not in (TF, BINARY, None)):
        self._update()
