class_docstr: Implementation of recurrent layers.
class_docstr_tok: ["Implementation","of","recurrent","layers","."]
code: def state_info(self, batch_size=0):
      raise NotImplementedError
  
imports: from ...None import np, npx, initializer, cpu
  from ..None import HybridBlock, tensor_types
  from ..parameter import Parameter
  from ...util import use_np
label_desc: Use image node_id 3 for calling the _RNNLayer obj's underlying member method code with example usage: obj.state_info(batch_size) without return types