input: Write a python function to determine the sentiment of a given sentence using TextBlob.
  assert determine_sentiment("I love sunny days") == "The sentiment is 'positive'"
  assert determine_sentiment("I hate rainy days") == "The sentiment is 'negative'"
  assert determine_sentiment("It's an average day") == "The sentiment is 'neutral'"
output: from textblob import TextBlob
  
  def determine_sentiment(sentence):
      analysis = TextBlob(sentence)
      polarity = analysis.sentiment.polarity
      
      if polarity > 0:
          return "The sentiment is 'positive'"
      elif polarity < 0:
          return "The sentiment is 'negative'"
      else:
          return "The sentiment is 'neutral'"