class_docstr: requires theta >=1
class_docstr_tok: ["requires","theta",">","=1"]
code: def deriv3_inverse(self, phi, theta):
      p = phi  # shorthand
      b = theta
      d3 = (
          -(p ** (3 / b))
          + (3 - 3 * b) * p ** (2 / b)
          + ((3 - 2 * b) * b - 1) * p ** (1 / b)
      ) / (p * b) ** 3
      d3 *= np.exp(-(p ** (1 / b)))
      return d3
  
imports: import warnings
  import numpy
  from scipy.special import expm1, gamma
label_desc: Use image node_id 7 for calling the TransfGumbel obj's underlying member method code with example usage: obj.deriv3_inverse(phi, theta) and returns: d3