code: def pdf(self, x):
      return self._pdf(x)
  
imports: import math
  import numbers
  import numpy
  from scipy import stats
  from scipy import special
  from ._qmc import check_random_state, Halton, QMCEngine
  from ._unuran.unuran_wrapper import NumericalInversePolynomial
  from scipy._lib._util import check_random_state
label_desc: Use image node_id 2 for calling the CustomDistPINV obj's underlying member method code with example usage: obj.pdf(x) and returns: self