code: def sum_recv(feat):
      return fluid.layers.sequence_pool(feat, pool_type="sum")
  
imports: from __future__ import division
  from __future__ import absolute_import
  from __future__ import print_function
  from __future__ import unicode_literals
  import math
  import pgl
  import numpy
  import paddle
  import paddle.fluid.layers
  import paddle.fluid
  import paddle.fluid
label_desc: Use image node_id 3 for calling a global function with example usage: sum_recv(feat) and returns: fluid