class_docstr: Encoder based on "Convolutional Sequence to Sequence Learning"
  :cite:`DBLP:journals/corr/GehringAGYD17`.
code: def update_dropout(self, dropout, attention_dropout=None):
      self.cnn.dropout.p = dropout
  
file_path: OpenNMT-py/onmt/encoders/cnn_encoder.py
imports: import torch.nn
  from onmt.encoders.encoder import EncoderBase
  from onmt.utils.cnn_factory import shape_transform, StackedCNN
label_desc: Use image node_id 4 for calling the CNNEncoder obj's underlying member method code with example usage: obj.update_dropout(dropout, attention_dropout) without return types