removeAttributeNS 方法
实现
@pragma('dart2js:tryInline')
void removeAttributeNS(String? namespaceURI, String name) {
// TODO(41258): Delete this assertion after forcing strong mode.
// Protect [name] against string conversion to "null" or "undefined".
assert(name != null, 'Attribute name cannot be null');
_removeAttributeNS(namespaceURI, name);
}