code: def phrase(min_size, max_size = None):
          
          max_size = max_size if max_size != None else min_size
          size = RandomInteger.next_integer(min_size, max_size)
          if size <= 0:
              return ""
          
          result = ""
          result += random.choice(_all_words)
          while len(result) < size:
              result += " " + random.choice(_all_words).lower()
  
          return result
docs: Generates a random phrase which consists of few words separated by spaces.
          The first word is capitalized, others are not.
  
          :param min_size: (optional) minimum string length.
  
          :param max_size: maximum string length.
  
          :return: a random phrase.