old_contents: from .base_roi_head import BaseRoIHead
  from .bbox_heads import (BBoxHead, ConvFCBBoxHead, DoubleConvFCBBoxHead,
                           SCNetBBoxHead, Shared2FCBBoxHead,
                           Shared4Conv1FCBBoxHead)
  from .cascade_roi_head import CascadeRoIHead
  from .double_roi_head import DoubleHeadRoIHead
  from .dynamic_roi_head import DynamicRoIHead
  from .grid_roi_head import GridRoIHead
  from .htc_roi_head import HybridTaskCascadeRoIHead
  from .mask_heads import (CoarseMaskHead, FCNMaskHead, FeatureRelayHead,
                           FusedSemanticHead, GlobalContextHead, GridHead,
                           HTCMaskHead, MaskIoUHead, MaskPointHead,
                           SCNetMaskHead, SCNetSemanticHead)
  from .mask_scoring_roi_head import MaskScoringRoIHead
  from .pisa_roi_head import PISARoIHead
  from .point_rend_roi_head import PointRendRoIHead
  from .roi_extractors import SingleRoIExtractor
  from .scnet_roi_head import SCNetRoIHead
  from .shared_heads import ResLayer
  from .sparse_roi_head import SparseRoIHead
  from .standard_roi_head import StandardRoIHead
  from .trident_roi_head import TridentRoIHead
  
  __all__ = [
      'BaseRoIHead', 'CascadeRoIHead', 'DoubleHeadRoIHead', 'MaskScoringRoIHead',
      'HybridTaskCascadeRoIHead', 'GridRoIHead', 'ResLayer', 'BBoxHead',
      'ConvFCBBoxHead', 'Shared2FCBBoxHead', 'StandardRoIHead',
      'Shared4Conv1FCBBoxHead', 'DoubleConvFCBBoxHead', 'FCNMaskHead',
      'HTCMaskHead', 'FusedSemanticHead', 'GridHead', 'MaskIoUHead',
      'SingleRoIExtractor', 'PISARoIHead', 'PointRendRoIHead', 'MaskPointHead',
      'CoarseMaskHead', 'DynamicRoIHead', 'SparseRoIHead', 'TridentRoIHead',
      'SCNetRoIHead', 'SCNetMaskHead', 'SCNetSemanticHead', 'SCNetBBoxHead',
      'FeatureRelayHead', 'GlobalContextHead'
  ]
  
new_contents: from .base_roi_head import BaseRoIHead
  from .bbox_heads import (BBoxHead, ConvFCBBoxHead, DIIHead,
                           DoubleConvFCBBoxHead, SABLHead, SCNetBBoxHead,
                           Shared2FCBBoxHead, Shared4Conv1FCBBoxHead)
  from .cascade_roi_head import CascadeRoIHead
  from .double_roi_head import DoubleHeadRoIHead
  from .dynamic_roi_head import DynamicRoIHead
  from .grid_roi_head import GridRoIHead
  from .htc_roi_head import HybridTaskCascadeRoIHead
  from .mask_heads import (CoarseMaskHead, FCNMaskHead, FeatureRelayHead,
                           FusedSemanticHead, GlobalContextHead, GridHead,
                           HTCMaskHead, MaskIoUHead, MaskPointHead,
                           SCNetMaskHead, SCNetSemanticHead)
  from .mask_scoring_roi_head import MaskScoringRoIHead
  from .pisa_roi_head import PISARoIHead
  from .point_rend_roi_head import PointRendRoIHead
  from .roi_extractors import (BaseRoIExtractor, GenericRoIExtractor,
                               SingleRoIExtractor)
  from .scnet_roi_head import SCNetRoIHead
  from .shared_heads import ResLayer
  from .sparse_roi_head import SparseRoIHead
  from .standard_roi_head import StandardRoIHead
  from .trident_roi_head import TridentRoIHead
  
  __all__ = [
      'BaseRoIHead', 'CascadeRoIHead', 'DoubleHeadRoIHead', 'MaskScoringRoIHead',
      'HybridTaskCascadeRoIHead', 'GridRoIHead', 'ResLayer', 'BBoxHead',
      'ConvFCBBoxHead', 'DIIHead', 'SABLHead', 'Shared2FCBBoxHead',
      'StandardRoIHead', 'Shared4Conv1FCBBoxHead', 'DoubleConvFCBBoxHead',
      'FCNMaskHead', 'HTCMaskHead', 'FusedSemanticHead', 'GridHead',
      'MaskIoUHead', 'BaseRoIExtractor', 'GenericRoIExtractor',
      'SingleRoIExtractor', 'PISARoIHead', 'PointRendRoIHead', 'MaskPointHead',
      'CoarseMaskHead', 'DynamicRoIHead', 'SparseRoIHead', 'TridentRoIHead',
      'SCNetRoIHead', 'SCNetMaskHead', 'SCNetSemanticHead', 'SCNetBBoxHead',
      'FeatureRelayHead', 'GlobalContextHead'
  ]
  
subject: Fix imports in roi_heads (#5007)