class_docstr: A single FPN cell.
code: def call(self, feats, training):
      @utils.recompute_grad(self.config.grad_checkpoint)
      def _call(feats):
          for fnode in self.fnodes:
              feats = fnode(feats, training)
          return feats
  
      return _call(feats)
  
imports: import functools
  from absl import logging
  import numpy
  import tensorflow
  import utils
  from .None import fpn_configs
label_desc: Use image node_id 2 for calling the FPNCell obj's underlying member method code with example usage: obj.call(feats, training) and returns: _call, feats