code: def apply_gradients(self, *gradients):
      self.net.apply_gradients(np.mean(gradients, axis=0))
      return self.net.variables.get_flat()
  
file_path: analytics-zoo/pyzoo/zoo/examples/ray_on_spark/parameter_server/sync_parameter_server.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import argparse
  import os
  from zoo.examples.ray_on_spark.parameter_server import model
  import numpy
  import ray
  from zoo.orca import init_orca_context, stop_orca_context
  from zoo.orca import OrcaContext
label_desc: Use image node_id 2 for calling the ParameterServer obj's underlying member method code with example usage: obj.apply_gradients() and returns: self