code: def count_call(self, call, axis=None):
          
          b = self.is_call(call=call)
          return np.sum(b, axis=axis)
docs: Count genotypes with a given call.
  
          Parameters
          ----------
          call : array_like, int, shape (ploidy,)
              The genotype call to find.
          axis : int, optional
              Axis over which to count, or None to perform overall count.