docs: def fit(
              self,
              data,
              states,
              estimator=None,
              complete_samples_only=True,
              **kwargs):
          """
          Determine βs from data
  
          Parameters
          ----------
          data: pandas.DataFrame
              Dataframe containing samples from the conditional distribution, p(Y|X)
              estimator: 'MLE' or 'MAP'
  
          completely_samples_only: boolean (True or False)
              Are they downsampled or complete? Defaults to True
  
          """
          if estimator == 'MLE':
              mean, variance = self.maximum_likelihood_estimator(data, states)
          elif estimator == 'MAP':
              raise NotImplementedError(
                  "fit method has not been implemented using Maximum A-Priori (MAP)")
  
          return mean, variance