code: def build_encoder_layer(self, args, layer_idx=None):
      return HeadSelectionTransformerEncoderLayer(
          args, layer_idx, attn_head_selector=self.attn_head_selector
      )
  
imports: from typing import Any, List, Dict, Optional
  import torch
  import torch.nn
  from torch import Tensor
  from fairseq.utils import safe_hasattr
  from fairseq.models.transformer import TransformerModel, TransformerEncoder, TransformerDecoder
  from ..modules.attn_head_selector import AttnHeadSelector
  from ..modules.head_selection_transformer_layer import HeadSelectionTransformerEncoderLayer, HeadSelectionTransformerDecoderLayer
label_desc: Use image node_id 3 for calling the HeadSelectionTransformerEncoder obj's underlying member method code with example usage: obj.build_encoder_layer(args, layer_idx) and returns: HeadSelectionTransformerEncoderLayer