code: def _get_ngrams(segment, max_order):
      """Extracts all n-grams upto a given maximum order from an input segment.
  
      Args:
        segment: text segment from which n-grams will be extracted.
        max_order: maximum length in tokens of the n-grams returned by this
            methods.
  
      Returns:
        The Counter containing all n-grams upto max_order in segment
        with a count of how many times each n-gram occurred.
      """
      ngram_counts = collections.Counter()
      for order in range(1, max_order + 1):
          for i in range(0, len(segment) - order + 1):
              ngram = tuple(segment[i : i + order])
              ngram_counts[ngram] += 1
      return ngram_counts
  
imports: import collections
  import math
label_desc: Use image node_id 1 for calling a global function with example usage: _get_ngrams(segment, max_order) and returns: ngram_counts