docstr: column names for summary table
          
docstr_tok: ["column","names","for","summary","table"]
code: def col_names(self):
      """column names for summary table"""
  
      pr_test = "P>%s" % self.distribution
      col_names = [self.distribution, pr_test, "df constraint"]
      if self.distribution == "F":
          col_names.append("df denom")
      return col_names
  
imports: import numpy
  from scipy.stats import f
  from scipy.stats import t
  from scipy import stats
  from statsmodels.tools.tools import clean0, fullrank
  from statsmodels.stats.multitest import multipletests
label_desc: Use image node_id 2 for calling the WaldTestResults obj's underlying member method code with example usage: obj.col_names() and returns: col_names