in lib/nano.js [964:980]
function insertAtt (docName, attName, att, contentType, qs0, callback0) {
const { opts, callback } = getCallback(qs0, callback0)
if (missing(docName, attName, att, contentType)) {
return callbackOrRejectError(callback)
}
return relax({
db: dbName,
att: attName,
method: 'PUT',
contentType,
doc: docName,
qs: opts,
body: att,
dontStringify: true
}, callback)
}