class_docstr: This module implements feed-forward network(after the Multi-Head Network) equation:
  FFN(x) = max(0, x @ W_1 + b_1) @ W_2 + b_2
code: def __init__(self, dim_model, dim_ff, dropout=0.1):
      super(PositionwiseFeedForward, self).__init__()
      self.w_1 = nn.Linear(dim_model, dim_ff)
      self.w_2 = nn.Linear(dim_ff, dim_model)
      self.dropout = nn.Dropout(dropout)
  
imports: import torch
  import torch.nn
  from torch.nn import LayerNorm
  import copy
label_desc: Use image node_id 1 to create a new PositionwiseFeedForward object from inherited base classes: nn with example: obj = PositionwiseFeedForward(dim_model, dim_ff, dropout)