code: def __call__(self, x):
      pred_bbox, pred_class = self.regression_head(
          x
      ), self.classification_head(x)
      out = pred_bbox.cat(pred_class, dim=-1)
      return out
  
imports: import math
  from tinygrad.helpers import flatten, get_child
  import tinygrad.nn
  from extra.models.resnet import ResNet
  import numpy
label_desc: Use image node_id 2 for calling the RetinaHead obj's underlying member method code with example usage: obj.__call__(x) and returns: out