🚑 fix message segment get

nonebot/adapters/__init__.py

@@ -286,6 +286,9 @@ class BaseMessageSegment(abc.ABC):
     def __setitem__(self, key, value):
         return setattr(self, key, value)
 
+    def get(self, key, default=None):
+        return getattr(self, key, default)
+
     @classmethod
     @abc.abstractmethod
     def text(cls, text: str) -> "BaseMessageSegment":