docstr: Check that the metric is supported by the KNNIndex instance.
docstr_tok: ["Check","that","the","metric","is","supported","by","the","KNNIndex","instance","."]
code: def check_metric(self, metric):
      """Check that the metric is supported by the KNNIndex instance."""
      if callable(metric):
          pass
      elif metric not in self.VALID_METRICS:
          raise ValueError(
              f"`{self.__class__.__name__}` does not support the `{metric}` "
              f"metric. Please choose one of the supported metrics: "
              f"{', '.join(self.VALID_METRICS)}."
          )
  
      return metric
  
imports: import logging
  import os
  import warnings
  import numpy
  from scipy.spatial.distance import cdist
  from sklearn import neighbors
  from sklearn.utils import check_random_state
  from openTSNE import utils
label_desc: Use image node_id 4 for calling the KNNIndex obj's underlying member method code with example usage: obj.check_metric(metric) and returns: metric