code: def build_ph(self):
      self.generator_obs_ph = tf.placeholder(
          tf.float32,
          (None,) + self.observation_shape,
          name="observations_ph",
      )
      self.generator_acs_ph = tf.placeholder(
          tf.float32, (None,) + self.actions_shape, name="actions_ph"
      )
      self.expert_obs_ph = tf.placeholder(
          tf.float32,
          (None,) + self.observation_shape,
          name="expert_observations_ph",
      )
      self.expert_acs_ph = tf.placeholder(
          tf.float32,
          (None,) + self.actions_shape,
          name="expert_actions_ph",
      )
  
file_path: baselines/baselines/gail/adversary.py
imports: import tensorflow
  import numpy
  from baselines.common.mpi_running_mean_std import RunningMeanStd
  from baselines.common import tf_util
label_desc: Use image node_id 2 for calling the TransitionClassifier obj's underlying member method code with example usage: obj.build_ph() without return types