input: Write a function to tokenize a given text using the `word_tokenize` function from the `nltk` library. The function should take a string as input and return a list of tokens.
  
  assert tokenize_text("Python is an interpreted, high-level, general-purpose programming language.")==['Python', 'is', 'an', 'interpreted', ',', 'high-level', ',', 'general-purpose', 'programming', 'language', '.']
  assert tokenize_text("NLTK is a powerful Python library for natural language processing.")==['NLTK', 'is', 'a', 'powerful', 'Python', 'library', 'for', 'natural', 'language', 'processing', '.']
  assert tokenize_text("")==[]
  assert tokenize_text("Hello, world!")==['Hello', ',', 'world', '!']
  assert tokenize_text("This is a test.")==['This', 'is', 'a', 'test', '.']
output: def tokenize_text(text):
      from nltk.tokenize import word_tokenize
      return word_tokenize(text)