chore: add repr to PageInfo class (#678)

Author: stainless-app[bot]

src/anthropic/_base_client.py

@@ -144,6 +144,12 @@ def __init__(
         self.url = url
         self.params = params
 
+    @override
+    def __repr__(self) -> str:
+        if self.url:
+            return f"{self.__class__.__name__}(url={self.url})"
+        return f"{self.__class__.__name__}(params={self.params})"
+
 
 class BasePage(GenericModel, Generic[_T]):
     """