input: Write a function to tokenize a given text using the NLTK library. The function should return a list of tokens. Use the function to tokenize the following text: 'Python is an interpreted, high-level, general-purpose programming language.'
  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('Natural Language Processing is fascinating.')==['Natural', 'Language', 'Processing', 'is', 'fascinating', '.']
  assert tokenize_text('')==[]
output: def tokenize_text(text):
      from nltk.tokenize import word_tokenize
      return word_tokenize(text)