Prefer set union over list concat
Prefer set union over list concat

CenterForOpenScience/osf.io,cslzchen/osf.io,CenterForOpenScience/osf.io,CenterForOpenScience/osf.io,cslzchen/osf.io,CenterForOpenScience/osf.io,cslzchen/osf.io,cslzchen/osf.io