host file with group headings leads to

$ ansible myhostgroup -m ping -u admin

bigboard5.local | success >> {
    "changed": false,
    "ping": "pong"
}

bigboard2.local | success >> {
    "changed": false,
    "ping": "pong"
}

bigboard1.local | success >> {
    "changed": false,
    "ping": "pong"
}

bigboard3.local | success >> {
    "changed": false,
    "ping": "pong"
}

bigboard4.local | success >> {
    "changed": false,
    "ping": "pong"
}

bigboard7.local | success >> {
    "changed": false,
    "ping": "pong"
}

bigboard6.local | success >> {
    "changed": false,
    "ping": "pong"
}