input: Write a python function to find the top five most common words in a given text. 
  assert top_five_common_words("Python is a powerful general-purpose programming language.") == [('a', 1), ('Python', 1), ('is', 1), ('powerful', 1), ('general', 1)]
  assert top_five_common_words("This is a test. This test is only a test.") == [('test', 3), ('This', 2), ('is', 2), ('a', 2), ('only', 1)]
  assert top_five_common_words("hello hello world world world") == [('world', 3), ('hello', 2)]
output: def top_five_common_words(text):
      from collections import Counter
      import re
      
      words = re.findall(r'\b\w+\b', text)
      word_counts = Counter(words)
      common_words = word_counts.most_common(5)
      return common_words