class_docstr: class for the probability distribution of total runs
  
  This is the exact probability distribution for the (Wald-Wolfowitz)
  runs test. The random variable is the total number of runs if the
  sample has (n0, n1) observations of groups 0 and 1.
  
  
  Notes
  -----
  Written as a class so I can store temporary calculations, but I do not
  think it matters much.
  
  Formulas taken from SAS manual for one-sided significance level.
  
  Could be converted to a full univariate distribution, subclassing
  scipy.stats.distributions.
  
  *Status*
  Not verified yet except for mean.
code: def __init__(self, n0, n1):
      self.n0 = n0
      self.n1 = n1
      self.n = n = n0 + n1
      self.comball = comb(n, n1)
  
imports: import numpy
  from scipy import stats
  from scipy.special import comb
  import warnings
  from statsmodels.tools.validation import array_like
label_desc: Use image node_id 1 to create a new TotalRunsProb object  with example: obj = TotalRunsProb(n0, n1)