TST: Add test case with example callback
TST: Add test case with example callback

arokem/scipy,lhilt/scipy,anntzer/scipy,perimosocordiae/scipy,jor-/scipy,perimosocordiae/scipy,mdhaber/scipy,e-q/scipy,endolith/scipy,rgommers/scipy,matthew-brett/scipy,grlee77/scipy,e-q/scipy,Stefan-Endres/scipy,aeklant/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,lhilt/scipy,anntzer/scipy,aarchiba/scipy,lhilt/scipy,rgommers/scipy,zerothi/scipy,matthew-brett/scipy,endolith/scipy,grlee77/scipy,andyfaff/scipy,andyfaff/scipy,person142/scipy,gertingold/scipy,Stefan-Endres/scipy,scipy/scipy,ilayn/scipy,andyfaff/scipy,anntzer/scipy,zerothi/scipy,arokem/scipy,mdhaber/scipy,Eric89GXL/scipy,perimosocordiae/scipy,jamestwebber/scipy,aeklant/scipy,endolith/scipy,person142/scipy,gertingold/scipy,ilayn/scipy,zerothi/scipy,anntzer/scipy,endolith/scipy,scipy/scipy,aarchiba/scipy,grlee77/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,lhilt/scipy,perimosocordiae/scipy,tylerjereddy/scipy,Eric89GXL/scipy,perimosocordiae/scipy,arokem/scipy,ilayn/scipy,ilayn/scipy,Stefan-Endres/scipy,scipy/scipy,e-q/scipy,WarrenWeckesser/scipy,vigna/scipy,matthew-brett/scipy,jor-/scipy,mdhaber/scipy,ilayn/scipy,aarchiba/scipy,jamestwebber/scipy,jor-/scipy,mdhaber/scipy,aarchiba/scipy,pizzathief/scipy,tylerjereddy/scipy,jor-/scipy,Eric89GXL/scipy,andyfaff/scipy,zerothi/scipy,scipy/scipy,zerothi/scipy,andyfaff/scipy,matthew-brett/scipy,Stefan-Endres/scipy,nmayorov/scipy,pizzathief/scipy,jamestwebber/scipy,anntzer/scipy,pizzathief/scipy,nmayorov/scipy,vigna/scipy,e-q/scipy,mdhaber/scipy,rgommers/scipy,e-q/scipy,aeklant/scipy,andyfaff/scipy,WarrenWeckesser/scipy,rgommers/scipy,person142/scipy,endolith/scipy,anntzer/scipy,mdhaber/scipy,aeklant/scipy,pizzathief/scipy,nmayorov/scipy,pizzathief/scipy,arokem/scipy,gertingold/scipy,WarrenWeckesser/scipy,matthew-brett/scipy,grlee77/scipy,zerothi/scipy,scipy/scipy,endolith/scipy,nmayorov/scipy,arokem/scipy,jamestwebber/scipy,tylerjereddy/scipy,tylerjereddy/scipy,vigna/scipy,jor-/scipy,Eric89GXL/scipy,tylerjereddy/scipy,jamestwebber/scipy,person142/scipy,lhilt/scipy,gertingold/scipy,vigna/scipy,aarchiba/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,person142/scipy,vigna/scipy,Eric89GXL/scipy,ilayn/scipy,grlee77/scipy,nmayorov/scipy,gertingold/scipy,scipy/scipy,aeklant/scipy,rgommers/scipy,WarrenWeckesser/scipy