code: def _info_rank(info, ch_type, picks, rank):
      if ch_type in ["meg", "mag", "grad"] and rank != "full":
          try:
              return _get_rank_sss(info)
          except ValueError:
              pass
      return len(picks)
  
file_path: mne-python/mne/rank.py
imports: import numpy
  from scipy import linalg
  from ._fiff.meas_info import Info, _simplify_info
  from ._fiff.pick import _picks_by_type, _picks_to_idx, pick_channels_cov, pick_info
  from ._fiff.proj import make_projector
  from .defaults import _handle_default
  from .utils import _apply_scaling_cov, _check_on_missing, _check_rank, _compute_row_norms, _on_missing, _pl, _scaled_array, _undo_scaling_cov, _validate_type, fill_doc, logger, verbose, warn
label_desc: Use image node_id 7 for calling a global function with example usage: _info_rank(info, ch_type, picks, rank) and returns: len, _get_rank_sss