add setattr magic method.

Author: d-w-moore

irods/meta.py

@@ -131,6 +131,19 @@ def __init__(self, operation, avu, **kw):
 
 
 class iRODSMetaCollection:
+    def __setattr__(self, name, value):
+        """Prevent the flag attributes such as 'admin', 'timestamps', etc., from
+        being changed in a way not sanctioned by the library.
+        """
+        from irods.manager.metadata_manager import _MetadataManager_opts_initializer
+
+        if name in _MetadataManager_opts_initializer:
+            msg = f"""The "{name}" attribute is a special one, settable only via a
+            call on the object.  For example: admin_view = data_obj.metadata({name}=<value>)"""
+            raise AttributeError(msg)
+
+        super().__setattr__(name, value)
+
     def __getattr__(self, name):
         """Here we intervene for the purpose of casting such settable flags such
         as 'admin', 'timestamps', etc. as readable attributes of the object.