static public BagArray url (String urlString, Bag postData, String postDataMimeType) {
        return url (urlString, postData, postDataMimeType, () -> null);
    }
static public BagArray url ( String urlString , Bag postData , String postDataMimeType ) { return url ( urlString , postData , postDataMimeType , ( ) -> null ) ; }
from a HTTP connection (post)