old_contents: # -*- coding: utf-8 -*-
  from flask_wtf import Form
  from flask_wtf.recaptcha import RecaptchaField, Recaptcha
  from wtforms import StringField, validators
  
  from .validation import url_validator
  
  
  class ShortenedURLForm(Form):
      url = StringField(
          validators=[
              validators.DataRequired(message='A target URL is required.'),
              validators.URL(message='A valid URL is required.'),
              url_validator.assert_not_blacklisted
          ],
          render_kw={'placeholder': 'Original URL'}
      )
      recaptcha = RecaptchaField(
          validators=[
              Recaptcha(
                  'Please click on the reCAPTCHA field '
                  'to prove you are a human.'
              )
          ]
      )
  
new_contents: # -*- coding: utf-8 -*-
  from flask_wtf import FlaskForm
  from flask_wtf.recaptcha import RecaptchaField, Recaptcha
  from wtforms import StringField, validators
  
  from .validation import url_validator
  
  
  class ShortenedURLForm(FlaskForm):
      url = StringField(
          validators=[
              validators.DataRequired(message='A target URL is required.'),
              validators.URL(message='A valid URL is required.'),
              url_validator.assert_not_blacklisted
          ],
          render_kw={'placeholder': 'Original URL'}
      )
      recaptcha = RecaptchaField(
          validators=[
              Recaptcha(
                  'Please click on the reCAPTCHA field '
                  'to prove you are a human.'
              )
          ]
      )
  
subject: Replace a depreciated import