code: def sum_recv(feat):
      """doc"""
      return L.sequence_pool(feat, pool_type="sum")
  
file_path: PGL/legacy/pgl/message_passing.py
imports: import numpy
  import paddle
  import paddle.fluid
  import paddle.fluid.layers
  from pgl.utils import paddle_helper
label_desc: Use image node_id 4 for calling a global function with example usage: sum_recv(feat) and returns: L