Given an left context `L`, punctuation mark `P`, and right context
        `R`, return True iff this observation is hypothesized to be a
        sentence boundary.

def predict(self, L, P, R):
        """
        Given an left context `L`, punctuation mark `P`, and right context
        `R`, return True iff this observation is hypothesized to be a
        sentence boundary.
        """
        phi = self.extract_one(L, P, R)
        return self.classifier.predict(phi)