Return the counter value of a token, from the counter table that
corresponds to the given token sequence.
If the token doesn't exist in the counter table, of the leading sequence
doesn't exist in the markov state, or the length of the sequence doesn't
match the size of the markov state, 0 is returned instead.
Return the counter value of a token, from the counter table that corresponds to the given token sequence. If the token doesn't exist in the counter table, of the leading sequence doesn't exist in the markov state, or the length of the sequence doesn't match the size of the markov state, 0 is returned instead.