class_docstr: SARIMAX parameters.
  
  Parameters
  ----------
  spec : SARIMAXSpecification
      Specification of the SARIMAX model.
  
  Attributes
  ----------
  spec : SARIMAXSpecification
      Specification of the SARIMAX model.
  exog_names : list of str
      Names associated with exogenous parameters.
  ar_names : list of str
      Names associated with (non-seasonal) autoregressive parameters.
  ma_names : list of str
      Names associated with (non-seasonal) moving average parameters.
  seasonal_ar_names : list of str
      Names associated with seasonal autoregressive parameters.
  seasonal_ma_names : list of str
      Names associated with seasonal moving average parameters.
  param_names :list of str
      Names of all model parameters.
  k_exog_params : int
      Number of parameters associated with exogenous variables.
  k_ar_params : int
      Number of parameters associated with (non-seasonal) autoregressive
      lags.
  k_ma_params : int
      Number of parameters associated with (non-seasonal) moving average
      lags.
  k_seasonal_ar_params : int
      Number of parameters associated with seasonal autoregressive lags.
  k_seasonal_ma_params : int
      Number of parameters associated with seasonal moving average lags.
  k_params : int
      Total number of model parameters.
code: def __init__(self, spec):
      self.spec = spec
  
      # Local copies of relevant attributes
      self.exog_names = spec.exog_names
      self.ar_names = spec.ar_names
      self.ma_names = spec.ma_names
      self.seasonal_ar_names = spec.seasonal_ar_names
      self.seasonal_ma_names = spec.seasonal_ma_names
      self.param_names = spec.param_names
  
      self.k_exog_params = spec.k_exog_params
      self.k_ar_params = spec.k_ar_params
      self.k_ma_params = spec.k_ma_params
      self.k_seasonal_ar_params = spec.k_seasonal_ar_params
      self.k_seasonal_ma_params = spec.k_seasonal_ma_params
      self.k_params = spec.k_params
  
      # Cache for holding parameter values
      self._params_split = spec.split_params(
          np.zeros(self.k_params) * np.nan, allow_infnan=True
      )
      self._params = None
  
imports: import numpy
  import pandas
  from numpy.polynomial import Polynomial
  from statsmodels.tsa.statespace.tools import is_invertible
  from statsmodels.tsa.arima.tools import validate_basic
label_desc: Use image node_id 1 to create a new SARIMAXParams object  with example: obj = SARIMAXParams(spec)