input: Write a function to generate n-grams of a given text with a specified window size. The function should return a Counter object containing the n-grams as keys and their counts as values.
  
  from collections import Counter
  
  def generate_ngrams(text, window_size):
      text = text.lower().split(' ')
      ngrams = []
      for n in range(window_size, len(text)+1):
          for i in range(len(text)-n+1):
              ngrams.append(' '.join(text[i:i+n]))
      return Counter(ngrams)
  
  text = "The quick brown fox jumps over the lazy dog"
  window_size = 3
  
  ngrams_count = generate_ngrams(text, window_size)
  
  print('\nNGRAMS COUNT:', ngrams_count)
  
  assert generate_ngrams("The quick brown fox jumps over the lazy dog", 3) == Counter({'the quick brown': 1, 'quick brown fox': 1, 'brown fox jumps': 1, 'fox jumps over': 1, 'jumps over the': 1, 'over the lazy': 1, 'the lazy dog': 1})
  assert generate_ngrams("The quick brown fox jumps over the lazy dog", 2) == Counter({'the quick': 1, 'quick brown': 1, 'brown fox': 1, 'fox jumps': 1, 'jumps over': 1, 'over the': 1, 'the lazy': 1, 'lazy dog': 1})
  assert generate_ngrams("", 3) == Counter()
  assert generate_ngrams("Testing", 1) == Counter({'testing': 1})
output: def generate_ngrams(text, window_size):
      text = text.lower().split(' ')
      ngrams = []
      for n in range(window_size, len(text)+1):
          for i in range(len(text)-n+1):
              ngrams.append(' '.join(text[i:i+n]))
      return Counter(ngrams)