class_docstr: Independent working covariance for QIF regression.  This covariance
  model gives identical results to GEE with the independence working
  covariance.  When using QIFIndependence as the working covariance,
  the QIF value will be zero, and cannot be used for chi^2 testing, or
  for model selection using AIC, BIC, etc.
code: def __init__(self):
      self.num_terms = 1
  
imports: import numpy
  from collections import defaultdict
  import statsmodels.base.model
  from statsmodels.genmod import families
  from statsmodels.genmod.generalized_linear_model import GLM
  from statsmodels.genmod.families import links
  from statsmodels.genmod.families import varfuncs
  import statsmodels.regression.linear_model
  import statsmodels.base.wrapper
  from statsmodels.tools.decorators import cache_readonly
label_desc: Use image node_id 1 to create a new QIFIndependence object from inherited base classes: QIFCovariance with example: obj = QIFIndependence()