code: def sample_pi(self, alpha, beta):
      Gam = tf.random_gamma(
          [1], alpha=alpha, beta=beta, name="Gam", seed=None
      )[0]
      return self.G_inv(Gam, alpha, beta)
  
file_path: cornac/cornac/models/pcrl/pcrl.py
imports: import numpy
  import scipy.sparse
  import scipy
  import tensorflow
label_desc: Use image node_id 9 for calling the PCRL_ obj's underlying member method code with example usage: obj.sample_pi(alpha, beta) and returns: self