old_contents: from flask_restx import fields  # noqa
  
  from app.api import api  # noqa
  
  
  # TODO: Add Serial model serializer here. And remove `HelloWorldSerializer`.
  
  HelloWorldSerializer = api.model('Hellow', {
      'id': fields.Integer(required=False, description='user identification number'),
      'name': fields.String(required=True, description='user full name', max_length=100, min_length=3),
      'role': fields.String(required=True, description='user role name', enum=['Admin', 'User', 'Operator']),
      'address': fields.String(required=False, description='user full address', max_length=200)})
  
new_contents: from flask_restx import fields
  
  from app.api import api
  
  
  TicketSerializer = api.model('Ticket', {
      'id': fields.Integer(required=False, description='ticket identification number.'),
      'number': fields.String(required=False, description='ticket number.'),
      'timestamp': fields.DateTime(required=False, description='date and time of ticket generation.'),
      'date': fields.DateTime(required=False, description='date of ticket generation.'),
      'name': fields.String(required=False, description='registered ticket stored value.'),
      'n': fields.Boolean(required=False, description='ticket is registered.'),
      'p': fields.Boolean(required=False, description='ticket is processed.'),
      'pdt': fields.DateTime(required=False, description='ticket pulled date and time.'),
      'pulledBy': fields.Integer(required=False, description='user id or token id that pulled ticket.'),
      'on_hold': fields.Boolean(required=False, description='ticket is put on hold.'),
      'status': fields.String(required=False, description='ticket processing status.'),
      'office_id': fields.Integer(required=False, description='office ticket belongs to.'),
      'task_id': fields.Integer(required=False, description='task ticket belongs to.'),
  })
  
  
  TaskSerializer = api.model('Task', {
      'id': fields.Integer(required=False, description='task identification number.'),
      'name': fields.String(required=False, description='task name.'),
      'timestamp': fields.DateTime(required=False, description='date and time of task creation.'),
      'hidden': fields.Boolean(required=False, description='task is is hidden in the touch screen.'),
  })
  
subject: Add tickets and tasks serializers.