Problem $1.($Markov Model Data Type$)$ Define a data type called MarkovModel in markov$\_$model.py to represent a Markov model of order k from a given text string. The data type must support the following API:$2$ MarkovModel

MarkovModel$($text$,$ k$)$ constructs a Markov model m of order k from text$$m$.$order$()$ returns the order of m$$m$.$kgram$\_$freq$($kgram$)$ returns the number of occurrences of kgram in m$$m$.$char$\_$freq$($kgram$,$ c$)$ returns the number of times character c follows kgram in m$$m$.$rand$($kgram$)$ using m$,$ finds and returns a random character following kgram$$m$.$gen$($kgram$,$ n$)$ using m$,$ builds and returns a string of length n$,$ the first k characters of which is kgram