input: from collections import Counter
  
  def generate_ngrams(text, window_size):
      """Generate n-grams of a given text with a specified window size.
      >>> ngrams_count = generate_ngrams("The quick brown fox jumps over the lazy dog", 3)
      >>> ngrams_count
      Counter({'the quick brown': 3, 'quick brown fox': 2, 'over the lazy': 1, 'brown fox jumps': 1, 'fox jumps over': 1, 'the lazy dog': 1, 'jumps over the': 1, 'quick brown fox jumps': 1})
      """
output:     ngrams = [text[i:i+window_size] for i in range(len(text) - window_size + 1)]
      return Counter(ngrams)