'Returns a Vector dict of (word, 0.0)-items from the vector space model.
It includes all words from all documents (i.e. it is the dimension of the vector space).
Model.vector(document) yields a vector with the feature weights of the given document.'

@property
def vector(self):

    if (not self._vector):
        self._vector = Vector(((w, 0.0) for w in chain(*(d.terms for d in self.documents))), sparse=False)
    return self._vector
