fixed set() to not re-set the same value
fixed set() to not re-set the same value

zzzeek/sqlalchemy,bdupharm/sqlalchemy,robin900/sqlalchemy,wfxiang08/sqlalchemy,brianv0/sqlalchemy,itkovian/sqlalchemy,halfcrazy/sqlalchemy,j5int/sqlalchemy,graingert/sqlalchemy,davidfraser/sqlalchemy,276361270/sqlalchemy,olemis/sqlalchemy,epa/sqlalchemy,bdupharm/sqlalchemy,alex/sqlalchemy,pdufour/sqlalchemy,alex/sqlalchemy,Cito/sqlalchemy,Akrog/sqlalchemy,halfcrazy/sqlalchemy,alex/sqlalchemy,Akrog/sqlalchemy,wujuguang/sqlalchemy,WinterNis/sqlalchemy,epa/sqlalchemy,inspirehep/sqlalchemy,robin900/sqlalchemy,Cito/sqlalchemy,sqlalchemy/sqlalchemy,j5int/sqlalchemy,dstufft/sqlalchemy,elelianghh/sqlalchemy,elelianghh/sqlalchemy,bootandy/sqlalchemy,inspirehep/sqlalchemy,wujuguang/sqlalchemy,276361270/sqlalchemy,davidfraser/sqlalchemy,graingert/sqlalchemy,dstufft/sqlalchemy,bootandy/sqlalchemy,monetate/sqlalchemy,hsum/sqlalchemy,WinterNis/sqlalchemy,Cito/sqlalchemy,wfxiang08/sqlalchemy,itkovian/sqlalchemy,davidjb/sqlalchemy,EvaSDK/sqlalchemy,ThiefMaster/sqlalchemy,sandan/sqlalchemy,monetate/sqlalchemy,brianv0/sqlalchemy,pdufour/sqlalchemy,EvaSDK/sqlalchemy,olemis/sqlalchemy,davidjb/sqlalchemy,hsum/sqlalchemy,sandan/sqlalchemy,ThiefMaster/sqlalchemy