input: Write a function to validate a list of emails. The function should return a boolean indicating whether a given email address is valid. If all emails are valid, return True; otherwise, return False.
  assert validate_mail_list(["example.user@gmail.com", "bad@example"])==False
  assert validate_mail_list(["user@example.com", "name.surname@domain.com"])==True
  assert validate_mail_list(["test@example.com", "invalid.email@"])==False
  assert validate_mail_list(["username@yahoo.com", "user.name@yahoo.co.uk"])==True
  assert validate_mail_list(["single@mail.com"])==True
output: def validate_mail_list(emails):
      import re
      pattern = r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$'
      for email in emails:
          if not re.match(pattern, email):
              return False
      return True