code: def init_hidden(self, features, feature_mask):
      average = paddle.sum(
          paddle.sum(features * feature_mask, axis=-1), axis=-1
      ) / paddle.sum((paddle.sum(feature_mask, axis=-1)), axis=-1)
      average = self.init_weight(average)
      return paddle.tanh(average)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import paddle.nn
  import paddle
  import math
label_desc: Use image node_id 3 for calling the AttDecoder obj's underlying member method code with example usage: obj.init_hidden(features, feature_mask) and returns: paddle