class_docstr: This class is adapted from the compacter implementation at https://github.com/rabeehk/compacter
code: def _init_W(self, W_left=None, W_right=None, W=None):
      if self.factorized_phm_W:
          W_left = W_left if W_left is not None else self.W_left
          W_right = W_right if W_right is not None else self.W_right
          return init_W(self.config, W_left, W_right, W)
      else:
          W = W if W is not None else self.W
          return init_W(self.config, W_left, W_right, W)
  
imports: import math
  import torch
  from torch import nn
  from transformers.activations import get_activation
  from ..configuration import AdapterFusionConfig, BnConfig
  from ..context import ForwardContext
label_desc: Use image node_id 2 for calling the PHMLayer obj's underlying member method code with example usage: obj._init_W(W_left, W_right, W) and returns: init_W, init_W