code: def A(self):
          
          wishart = self._wishart_cdf
  
          base = np.zeros([wishart.size, wishart.size])
          if wishart.n_min % 2:
              # If matrix has odd number of elements, we need to append a
              # row and a col, in order for the pfaffian algorithm to work
              base = self._make_size_even(base)
          return base
docs: ndarray - a skew-symmetric matrix for integrating the target distribution