code: def __init__(
      self,
      in_channels,
      key_channels,
      value_channels,
      out_channels=None,
      scale=1,
  ):
      super(SelfAttentionBlock2D, self).__init__(
          in_channels, key_channels, value_channels, out_channels, scale
      )
  
imports: import torch
  import torch.nn.functional
  from torch import nn
  from ..modules.activations import ABN
label_desc: Use image node_id 1 to create a new SelfAttentionBlock2D object from inherited base classes: _SelfAttentionBlock with example: obj = SelfAttentionBlock2D(in_channels, key_channels, value_channels, out_channels, scale)