old_contents: from statsmodels.regression.linear_model import GLS
  gls = GLS.from_formula
  from statsmodels.regression.linear_model import WLS
  wls = WLS.from_formula
  from statsmodels.regression.linear_model import OLS
  ols = OLS.from_formula
  from statsmodels.regression.linear_model import GLSAR
  glsar = GLSAR.from_formula
  from statsmodels.regression.mixed_linear_model import MixedLM
  mixedlm = MixedLM.from_formula
  from statsmodels.genmod.generalized_linear_model import GLM
  glm = GLM.from_formula
  from statsmodels.robust.robust_linear_model import RLM
  rlm = RLM.from_formula
  from statsmodels.discrete.discrete_model import MNLogit
  mnlogit = MNLogit.from_formula
  from statsmodels.discrete.discrete_model import Logit
  logit = Logit.from_formula
  from statsmodels.discrete.discrete_model import Probit
  probit = Probit.from_formula
  from statsmodels.discrete.discrete_model import Poisson
  poisson = Poisson.from_formula
  from statsmodels.discrete.discrete_model import NegativeBinomial
  negativebinomial = NegativeBinomial.from_formula
  from statsmodels.regression.quantile_regression import QuantReg
  quantreg = QuantReg.from_formula
  from statsmodels.duration.hazard_regression import PHReg
  phreg = PHReg.from_formula
  from statsmodels.genmod.generalized_estimating_equations import (GEE,
       OrdinalGEE, NominalGEE)
  gee = GEE.from_formula
  ordinal_gee = OrdinalGEE.from_formula
  nominal_gee = NominalGEE.from_formula
  
new_contents: import statsmodels.regression.linear_model as lm
  import statsmodels.discrete.discrete_model as dm
  import statsmodels.regression.mixed_linear_model as mlm
  import statsmodels.genmod.generalized_linear_model as glm
  import statsmodels.robust.robust_linear_model as roblm
  import statsmodels.regression.quantile_regression as qr
  import statsmodels.duration.hazard_regression as hr
  import statsmodels.genmod.generalized_estimating_equations as gee
  
  gls = lm.GLS.from_formula
  wls = lm.WLS.from_formula
  ols = lm.OLS.from_formula
  glsar = lm.GLSAR.from_formula
  mixedlm = mlm.MixedLM.from_formula
  glm = glm.GLM.from_formula
  rlm = roblm.RLM.from_formula
  mnlogit = dm.MNLogit.from_formula
  logit = dm.Logit.from_formula
  probit = dm.Probit.from_formula
  poisson = dm.Poisson.from_formula
  negativebinomial = dm.NegativeBinomial.from_formula
  quantreg = qr.QuantReg.from_formula
  phreg = hr.PHReg.from_formula
  ordinal_gee = gee.OrdinalGEE.from_formula
  nominal_gee = gee.NominalGEE.from_formula
  gee = gee.GEE.from_formula
  
  del lm, dm, mlm, glm, roblm, qr, hr
  
subject: clean up smf namespace