new extension method for IsSelectMany() in the linq support
new extension method for IsSelectMany() in the linq support

jokokko/marten,JasperFx/Marten,ericgreenmix/marten,jmbledsoe/marten,mysticmind/marten,mysticmind/marten,mdissel/Marten,jamesfarrer/marten,tim-cools/Marten,jokokko/marten,JasperFx/Marten,mysticmind/marten,jamesfarrer/marten,JasperFx/Marten,mysticmind/marten,jokokko/marten,jmbledsoe/marten,tim-cools/Marten,jamesfarrer/marten,jmbledsoe/marten,jmbledsoe/marten,ericgreenmix/marten,jamesfarrer/marten,jokokko/marten,mdissel/Marten,ericgreenmix/marten,jokokko/marten,tim-cools/Marten,jmbledsoe/marten,ericgreenmix/marten