class_docstr: Diagnostic and specification tests and plots for Poisson model
  
  status: experimental
  
  Parameters
  ----------
  results : PoissonResults instance
docstr: Test for excess (over or under) dispersion in Poisson.
  
  Returns
  -------
  dispersion results
docstr_tok: ["Test","for","excess","(","over","or","under",")","dispersion","in","Poisson",".","Returns","--","--","--","-","dispersion","results"]
code: def test_dispersion(self):
      """Test for excess (over or under) dispersion in Poisson.
  
      Returns
      -------
      dispersion results
      """
      res = test_poisson_dispersion(self.results)
      return res
  
file_path: statsmodels/statsmodels/discrete/diagnostic.py
imports: import warnings
  import numpy
  from statsmodels.tools.decorators import cache_readonly
  from statsmodels.stats.diagnostic_gen import test_chisquare_binning
  from statsmodels.discrete._diagnostics_count import test_poisson_dispersion, test_poisson_zeroinflation_jh, test_poisson_zeroinflation_broek, test_poisson_zeros, test_chisquare_prob, plot_probs
label_desc: Use image node_id 2 for calling the PoissonDiagnostic obj's underlying member method code with example usage: obj.test_dispersion() and returns: res