input: Write a function to send an email using Celery in Python. The function should accept recipient_name, recipient_email, subject, and message as parameters, and send an email using Flask-Mail. If the email is sent successfully, return True, otherwise return False.
  
  from celery import Celery
  from flask_mail import Message
  
  app = Celery('tasks', backend='redis://localhost')
  
  @app.task
  def send_email(recipient_name, recipient_email, subject, message):
      msg = Message(subject, sender='example@example.com', recipients=[recipient_email])
      msg.body = f"Dear {recipient_name}, {message}"
      try:
          mail.send(msg)
          return True
      except Exception as e:
          return False
  
  assert send_email('John Smith', 'john@example.com', 'Hello World', 'This is a test email.') == True
  assert send_email('Jane Doe', 'jane@example.info', 'Greetings', 'This is a different test.') == True
  assert send_email('Invalid Name', 'invalid_email', 'Error Test', 'This should fail.') == False
  assert send_email('', '', '', '') == False
output: 
  def send_email(recipient_name, recipient_email, subject, message):
      msg = Message(subject, sender='example@example.com', recipients=[recipient_email])
      msg.body = f"Dear {recipient_name}, {message}"
      try:
          mail.send(msg)
          return True
      except Exception as e:
          return False
  