input: Write a python function to find all occurrences of the pattern "word1 word2" in a given string.
  assert find_pattern("word1 word2, other text, word1 word2") == ['word1 word2', 'word1 word2']
  assert find_pattern("word1 other word2 word1 word2") == ['word1 word2']
  assert find_pattern("no match here") == []
output: def find_pattern(text):
      import re
      return re.findall(r'word1 word2', text)