我有麻烦，我需要从草图文件中解码base64并获取json，但是当我这样做时，我得到的不是json .
Base64编码
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
我的代码
b, err := base64.StdEncoding.DecodeString(fontString)
if err != nil {
log.Fatal(err)
}
fmt.Printf(string(b))
这是我得到的（不完整版，完整版很大）
bplist00 ??? X $ versionX $ objectsY $ archiverT $顶部???％＆'（）* 6789：AEMPSV_eimqtv ???? U $空？
XNSString_NSAttributeInfo \ NSAttributesV $类？ ??！YMORE INFO？ ZNS.objects ????? $ WNS.keys ???? ！“＃?? ??? VNSKern_MSAttributedStringFontAttribute_NSParagraphStyleWNSColor＃@ 33 @ ?, - NSFontDescriptorAttributes ??