text: ALLOWED_EXTENSIONS = {'png', 'jpg', 'jpeg', 'md', 'stl', 'dwg', 'dxf', 'svg'}
  
  def valid_email(email):
      return True if email.endswith('@cooper.edu') else False
  
  def allowed_file(filename):
      return '.' in filename and \
          filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS