code: def transform_params(self, unconstrained):
      # Perform the typical DFM transformation (w/o the new parameters)
      constrained = super().transform_params(unconstrained[:-3])
  
      # Redo the factor AR constraint, since we only want an AR(2),
      # and the previous constraint was for an AR(4)
      ar_params = unconstrained[self._params_factor_ar]
      constrained[
          self._params_factor_ar
      ] = tools.constrain_stationary_univariate(ar_params)
  
      # Return all the parameters
      return np.r_[constrained, unconstrained[-3:]]
  
file_path: statsmodels/examples/python/statespace_dfm_coincident.py
imports: import numpy
  import pandas
  import statsmodels.api
  import matplotlib.pyplot
  from pandas_datareader.data import DataReader
  from statsmodels.tsa.statespace import tools
label_desc: Use image node_id 4 for calling the ExtendedDFM obj's underlying member method code with example usage: obj.transform_params(unconstrained) and returns: np