class_docstr: This module implements :paper:`FPN`.
  It creates pyramid features built on top of some input feature maps.
class_docstr_tok: ["This","module","implements",":","paper",":","`","FPN","`",".","It","creates","pyramid","features","built","on","top","of","some","input","feature","maps","."]
code: def output_shape(self):
      return {
          name: ShapeSpec(
              channels=self._out_feature_channels[name],
              stride=self._out_feature_strides[name],
          )
          for name in self._out_features
      }
  
imports: import math
  import fvcore.nn.weight_init
  import torch
  import torch.nn.functional
  from torch import nn
  from detectron2.layers import Conv2d, ShapeSpec, get_norm
  from .backbone import Backbone
  from .build import BACKBONE_REGISTRY
  from .resnet import build_resnet_backbone
label_desc: Use image node_id 5 for calling the FPN obj's underlying member method code with example usage: obj.output_shape() and returns: unknown