input: Write a python function to perform word lemmatization on a given text.
  assert lemmatize_text("running runs ran") == "running run ran"
  assert lemmatize_text("better best good") == "better best good"
  assert lemmatize_text("cats are running") == "cat are running"
output: def lemmatize_text(text):
      import nltk
      from nltk.stem import WordNetLemmatizer
      from nltk.tokenize import word_tokenize
      from nltk.corpus import wordnet
  
      nltk.download('punkt')
      nltk.download('wordnet')
  
      lemmatizer = WordNetLemmatizer()
      words = word_tokenize(text)
      lemmatized_words = [lemmatizer.lemmatize(word, pos=wordnet.VERB) for word in words]
  
      return ' '.join(lemmatized_words)