input: Write a function to tokenize a given text. The function should return a list of tokens. If the input text is empty, the function should return an empty list.
  import nltk 
  from nltk.tokenize import word_tokenize 
  
  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('')==[]
  assert tokenize_text('Hello World!')==['Hello', 'World', '!']
  assert tokenize_text('This is a test.')==['This', 'is', 'a', 'test', '.']
  assert tokenize_text('Tokenization is important.')==['Tokenization', 'is', 'important', '.']
output: def tokenize_text(text):
      if not text:
          return []
      return word_tokenize(text)