code: def available_metrics() -> Dict[str, List[str]]:
      """
      Retrieve the available metrics in Quantus.
  
      Returns
      -------
      Dict[str, str]
          With the available metrics, under each category in Quantus.
      """
      return {
          c: list(metrics.keys())
          for c, metrics in AVAILABLE_METRICS.items()
      }
  
file_path: Quantus/quantus/helpers/constants.py
imports: import sys
  from typing import List, Dict, Mapping, Type
  from quantus.functions.loss_func import *
  from quantus.functions.normalise_func import *
  from quantus.functions.perturb_func import *
  from quantus.functions.similarity_func import *
  from quantus.functions import n_bins_func
  from quantus.metrics import *
label_desc: Use image node_id 2 for calling a global function with example usage: available_metrics() and returns: unknown