Fix a bug in the signature of __new__.
Fix a bug in the signature of __new__.

Also, Python special-cases __new__ so you don't need to specify
@classmethod.

Reviewed at https://rbcommons.com/s/twitter/r/880/

lahosken/pants,mateor/pants,scode/pants,jtrobec/pants,tdyas/pants,benjyw/pants,tdyas/pants,twitter/pants,ericzundel/pants,qma/pants,15Dkatz/pants,qma/pants,peiyuwang/pants,areitz/pants,landism/pants,square/pants,foursquare/pants,dturner-tw/pants,dgomez10/xanon,pgroudas/pants,jessrosenfield/pants,scode/pants,15Dkatz/pants,kslundberg/pants,Gabriel439/pants,manasapte/pants,ericzundel/pants,dbentley/pants,dbentley/pants,jtrobec/pants,digwanderlust/pants,sid-kap/pants,dgomez10/xanon,tejal29/pants,Gabriel439/pants,foursquare/pants,manasapte/pants,kslundberg/pants,pgroudas/pants,manasapte/pants,square/pants,megaserg/pants,qma/pants,lahosken/pants,dgomez10/xanon,ericzundel/pants,benjyw/pants,pombredanne/pants,tdyas/pants,foursquare/pants,areitz/pants,15Dkatz/pants,jtrobec/pants,dgomez10/xanon,dbentley/pants,benjyw/pants,dturner-tw/pants,pantsbuild/pants,lahosken/pants,gmalmquist/pants,di0spyr0s/pants,kwlzn/pants,peiyuwang/pants,jessrosenfield/pants,slyphon/pants,fkorotkov/pants,foursquare/pants,gmalmquist/pants,TansyArron/pants,UnrememberMe/pants,dgomez10/xanon,TansyArron/pants,digwanderlust/pants,scode/pants,pombredanne/pants,pantsbuild/pants,TansyArron/pants,benjyw/pants,ity/pants,mateor/pants,jessrosenfield/pants,peiyuwang/pants,manasapte/pants,landism/pants,mateor/pants,pombredanne/pants,pantsbuild/pants,ericzundel/pants,sameerparekh/pants,square/pants,tdyas/pants,UnrememberMe/pants,landism/pants,peiyuwang/pants,qma/pants,qma/pants,15Dkatz/pants,UnrememberMe/pants,wisechengyi/pants,sameerparekh/pants,gmalmquist/pants,wisechengyi/pants,areitz/pants,TansyArron/pants,peiyuwang/pants,wisechengyi/pants,pombredanne/pants,sid-kap/pants,dturner-tw/pants,areitz/pants,sameerparekh/pants,wisechengyi/pants,cevaris/pants,lahosken/pants,benjyw/pants,laurentgo/pants,tdyas/pants,dgomez10/xanon,cevaris/pants,tdyas/pants,peiyuwang/pants,TansyArron/pants,Gabriel439/pants,sameerparekh/pants,ericzundel/pants,digwanderlust/pants,laurentgo/pants,tdyas/pants,slyphon/pants,laurentgo/pants,ericzundel/pants,lahosken/pants,dbentley/pants,gmalmquist/pants,baroquebobcat/pants,ericzundel/pants,scode/pants,kwlzn/pants,slyphon/pants,baroquebobcat/pants,sid-kap/pants,baroquebobcat/pants,benjyw/pants,gmalmquist/pants,dgomez10/xanon,dgomez10/xanon,dturner-tw/pants,jessrosenfield/pants,baroquebobcat/pants,scode/pants,manasapte/pants,square/pants,twitter/pants,jtrobec/pants,landism/pants,pantsbuild/pants,dgomez10/xanon,laurentgo/pants,scode/pants,slyphon/pants,sid-kap/pants,wisechengyi/pants,Gabriel439/pants,Gabriel439/pants,baroquebobcat/pants,areitz/pants,digwanderlust/pants,sameerparekh/pants,lahosken/pants,baroquebobcat/pants,pantsbuild/pants,wisechengyi/pants,wisechengyi/pants,baroquebobcat/pants,landism/pants,kwlzn/pants,pgroudas/pants,baroquebobcat/pants,fkorotkov/pants,jtrobec/pants,megaserg/pants,fkorotkov/pants,wisechengyi/pants,jessrosenfield/pants,dbentley/pants,twitter/pants,landism/pants,sameerparekh/pants,Gabriel439/pants,jtrobec/pants,manasapte/pants,UnrememberMe/pants,tejal29/pants,megaserg/pants,megaserg/pants,ity/pants,jessrosenfield/pants,UnrememberMe/pants,twitter/pants,15Dkatz/pants,pgroudas/pants,wisechengyi/pants,ity/pants,dbentley/pants,dgomez10/xanon,qma/pants,cevaris/pants,UnrememberMe/pants,ity/pants,di0spyr0s/pants,dbentley/pants,foursquare/pants,fkorotkov/pants,TansyArron/pants,jessrosenfield/pants,twitter/pants,tdyas/pants,sameerparekh/pants,15Dkatz/pants,foursquare/pants,kwlzn/pants,UnrememberMe/pants,pombredanne/pants,mateor/pants,gmalmquist/pants,digwanderlust/pants,twitter/pants,cevaris/pants,jsirois/pants,fkorotkov/pants,mateor/pants,kwlzn/pants,scode/pants,15Dkatz/pants,twitter/pants,slyphon/pants,megaserg/pants,slyphon/pants,foursquare/pants,gmalmquist/pants,ericzundel/pants,pantsbuild/pants,ity/pants,lahosken/pants,15Dkatz/pants,kslundberg/pants,sid-kap/pants,pantsbuild/pants,cevaris/pants,cevaris/pants,benjyw/pants,cevaris/pants,pgroudas/pants,megaserg/pants,dturner-tw/pants,digwanderlust/pants,manasapte/pants,di0spyr0s/pants,sid-kap/pants,dgomez10/xanon,pombredanne/pants,laurentgo/pants,dturner-tw/pants,fkorotkov/pants,kwlzn/pants,jsirois/pants,pgroudas/pants,UnrememberMe/pants,mateor/pants,laurentgo/pants,kslundberg/pants,mateor/pants,Gabriel439/pants,di0spyr0s/pants,jtrobec/pants,sid-kap/pants,areitz/pants,fkorotkov/pants,mateor/pants,baroquebobcat/pants,kslundberg/pants,ity/pants,twitter/pants,areitz/pants,tejal29/pants,landism/pants,kwlzn/pants,pombredanne/pants,UnrememberMe/pants,kslundberg/pants,lahosken/pants,peiyuwang/pants,jsirois/pants,twitter/pants,landism/pants,TansyArron/pants,di0spyr0s/pants,tejal29/pants,ity/pants,dturner-tw/pants,di0spyr0s/pants,foursquare/pants,slyphon/pants,kslundberg/pants,peiyuwang/pants,tdyas/pants,di0spyr0s/pants,fkorotkov/pants,qma/pants,foursquare/pants,megaserg/pants,tejal29/pants