old_contents: from .attention_layer import AttentionLayer
  from .multi_perspective_layer import MultiPerspectiveLayer
  from .matching_tensor_layer import MatchingTensorLayer
  from .spatial_gru import SpatialGRU
  from .decaying_dropout_layer import DecayingDropoutLayer
  from .encoding_layer import EncodingLayer
  
  layer_dict = {
      "MatchingTensorLayer": MatchingTensorLayer,
      "SpatialGRU": SpatialGRU,
  	"DecayingDropoutLayer": DecayingDropoutLayer,
      "EncodingLayer": EncodingLayer
  }
  
new_contents: from .attention_layer import AttentionLayer
  from .multi_perspective_layer import MultiPerspectiveLayer
  from .matching_tensor_layer import MatchingTensorLayer
  from .spatial_gru import SpatialGRU
  from .decaying_dropout_layer import DecayingDropoutLayer
  from .encoding_layer import EncodingLayer
  
  layer_dict = {
      "MatchingTensorLayer": MatchingTensorLayer,
      "SpatialGRU": SpatialGRU,
      "DecayingDropoutLayer": DecayingDropoutLayer,
      "EncodingLayer": EncodingLayer
  }
  
subject: fix contrib/layers/__init__.py