code: def __call__(self, imgs):
      from ..regions import signal_extraction
  
      return signal_extraction.img_to_signals_maps(
          imgs,
          self._resampled_maps_img_,
          mask_img=self._resampled_mask_img_,
          keep_masked_maps=self.keep_masked_maps,
      )
  
file_path: nilearn/nilearn/maskers/nifti_maps_masker.py
imports: import warnings
  import numpy
  from joblib import Memory
  from nilearn import _utils, image
  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: signal_extraction