class_docstr: A flattening block.
  
  :param in_keys: One key identifying the input tensors.
  :param out_keys: One key identifying the output tensors.
  :param in_shapes: List of input shapes.
  :param num_flatten_dims: the number of dimensions to flatten out (from right).
code: def __init__(
      self,
      in_keys: Union[str, List[str]],
      out_keys: Union[str, List[str]],
      in_shapes: Union[Sequence[int], List[Sequence[int]]],
      num_flatten_dims: int,
  ):
      super().__init__(
          in_keys=in_keys, out_keys=out_keys, in_shapes=in_shapes
      )
      self.num_flatten_dims = num_flatten_dims
  
file_path: maze/maze/perception/blocks/general/flatten.py
imports: from typing import Union, List, Sequence, Dict
  import torch
  from maze.core.annotations import override
  from maze.perception.blocks.base import PerceptionBlock
label_desc: Use image node_id 1 to create a new FlattenBlock object from inherited base classes: PerceptionBlock with example: obj = FlattenBlock(in_keys, out_keys, in_shapes, num_flatten_dims)