docs: def get_hgp(p, k, N, K, n):
      """Calculate the hypergeometric p-value when p = f(k; N,K,n) is already known.
      """
      pval = p
      while k < min(K, n):
          p *= (float((n-k)*(K-k) / float((k+1)*(N-K-n+k+1))))
          pval += p
          k += 1
      return pval