class_docstr: Implement BiLSTM encoder module in `ASTER: An Attentional Scene Text
  Recognizer with Flexible Rectification.
  
  <https://ieeexplore.ieee.org/abstract/document/8395027/`
  Args:
      in_channels (int): Number of input channels.
      num_layers (int): Layers of BiLSTM. Defaults to 2.
code: def __init__(
      self,
      in_channels: int,
      num_layers: int = 2,
      init_cfg=dict(type="Xavier", layer="Conv2d"),
  ) -> None:
      super().__init__(init_cfg=init_cfg)
      self.bilstm = nn.LSTM(
          in_channels,
          in_channels // 2,
          num_layers=num_layers,
          bidirectional=True,
          batch_first=True,
      )
  
imports: import torch
  import torch.nn
  from mmocr.registry import MODELS
  from .base import BaseEncoder
label_desc: Use image node_id 1 to create a new ASTEREncoder object from inherited base classes: BaseEncoder with example: obj = ASTEREncoder(in_channels, num_layers, init_cfg)