docstr: Get min/max values for each band in the image
docstr_tok: ["Get","min\/max","values","for","each","band","in","the","image"]
code: def _getextrema(self):
      """Get min/max values for each band in the image"""
  
      def minmax(histogram):
          n = 255
          x = 0
          for i in range(256):
              if histogram[i]:
                  n = min(n, i)
                  x = max(x, i)
          return (
              n,
              x,
          )  # returns (255, 0) if there's no data in the histogram
  
      v = []
      for i in range(0, len(self.h), 256):
          v.append(minmax(self.h[i:]))
      return v
  
file_path: catboost/contrib/python/Pillow/py2/PIL/ImageStat.py
imports: import functools
  import math
  import operator
label_desc: Use image node_id 3 for calling the Stat obj's underlying member method code with example usage: obj._getextrema() and returns: v, n,  x