old_contents: """Request/Response Schemas are defined here"""
  # pylint: disable=invalid-name
  
  from marshmallow import Schema, fields
  
  
  class TaskSchema(Schema):
      """Schema for api.portal.models.Panel"""
      id = fields.Int(required=True)
      title = fields.Str(required=True)
      description = fields.Str(required=True)
      status = fields.Str(required=True)
      created_at = fields.DateTime(required=True)
      updated_at = fields.DateTime(required=True)
  
new_contents: """Request/Response Schemas are defined here"""
  # pylint: disable=invalid-name
  
  from marshmallow import Schema, fields, validate
  
  from todo.constants import TO_DO, IN_PROGRESS, DONE
  
  
  class TaskSchema(Schema):
      """Schema for serializing an instance of Task"""
      id = fields.Int(required=True)
      title = fields.Str(required=True)
      description = fields.Str(required=True)
      status = fields.Str(
          required=True,
          validate=validate.OneOf(
              choices=[TO_DO, IN_PROGRESS, DONE],
              error="Status must be one of {choices} (given: {input})"))
      number = fields.Int(required=True)
      created_at = fields.DateTime(required=True)
      updated_at = fields.DateTime(required=True)
  
  
  class BoardSchema(Schema):
      """Schema for serializing an instance of Board"""
      id = fields.Int(required=True)
      name = fields.Str(required=True)
      created_at = fields.DateTime(required=True)
      updated_at = fields.DateTime(required=True)
  
  
  class BoardDetailsSchema(BoardSchema):
      """Schema for serializing an instance of Board and its tasks"""
      tasks = fields.Nested(TaskSchema, many=True)
  
subject: add BoardSchema, BoardDetailsSchema and add refactor TaskSchema to include `number` field and status validation