`Feed`: add the `.duplicate_of` attribute, remove an unused one.
`Feed`: add the `.duplicate_of` attribute, remove an unused one.

WillianPaiva/1flow,1flow/1flow,1flow/1flow,1flow/1flow,WillianPaiva/1flow,WillianPaiva/1flow,1flow/1flow,WillianPaiva/1flow,1flow/1flow,WillianPaiva/1flow