code: def group_demean(self, x, use_bincount=True):
      nobs = float(len(x))
      means_g = group_sums(
          x / nobs, self.group_int, use_bincount=use_bincount
      )
      x_demeaned = x - means_g[self.group_int]  # check reverse_index?
      return x_demeaned, means_g
  
imports: from statsmodels.compat.python import lrange, lzip
  import numpy
  import pandas
  import statsmodels.tools.data
  from pandas import Index, MultiIndex
label_desc: Use image node_id 7 for calling the Group obj's underlying member method code with example usage: obj.group_demean(x, use_bincount) and returns: x_demeaned,  means_g