'Return a tuple of form (polarity, subjectivity ) where polarity
is a float within the range [-1.0, 1.0] and subjectivity is a float
within the range [0.0, 1.0] where 0.0 is very objective and 1.0 is
very subjective.
:rtype: namedtuple of the form ``Sentiment(polarity, subjectivity)``'

@cached_property
def sentiment(self):

    return self.analyzer.analyze(self.raw)
