[Unit]
Description=Test for Supplementary Group with only one group

[Service]
ExecStart=/bin/sh -x -c 'HAVE=; for g in $$(id -G); do test "$$g" = "1" && HAVE=1; done; test "$$HAVE" -eq 1'
ExecStart=/bin/sh -x -c 'test "$$(id -g)" = "1" && test "$$(id -u)" = "0"'
Type=oneshot
Group=1
SupplementaryGroups=1