code: def __call__(self, imgs):
      from ..regions.signal_extraction import img_to_signals_labels
  
      signals, labels, masked_labels_img = img_to_signals_labels(
          imgs,
          self._resampled_labels_img_,
          background_label=self.background_label,
          strategy=self.strategy,
          keep_masked_labels=self.keep_masked_labels,
          mask_img=self.mask_img,
          return_masked_atlas=True,
      )
      return signals, (labels, masked_labels_img)
  
file_path: nilearn/nilearn/maskers/nifti_labels_masker.py
imports: import warnings
  import numpy
  from joblib import Memory
  from nilearn import _utils, image, masking
  from nilearn.maskers._utils import compute_middle_image
  from nilearn.maskers.base_masker import BaseMasker, _filter_and_extract
label_desc: Use image node_id 2 for calling the _ExtractionFunctor obj's underlying member method code with example usage: obj.__call__(imgs) and returns: signals,  labels,  masked_labels_img