wb_wdi: Correct data.

sdmx/source/wb_wdi.py

@@ -13,8 +13,17 @@ def modify_request_args(self, kwargs):
             # Service does not respond to requests for "WB" category schemes
             kwargs["provider"] = "all"
         elif kwargs.get("resource_type") == Resource.data:
-            # Provider's own ID differs from its ID in this package
-            kwargs.setdefault("provider", "WB")
+            # In this case, the agency_id comes before the resource_id
+            # Invert key and resource_id exceptionally.
+            kwargs.setdefault("agency_id", "WDI")
+            if not isinstance(kwargs["key"], str):
+                raise ValueError(
+                    "WDI data currently only supports strings as keys"
+                )
+            key = kwargs.get("resource_id")
+            kwargs.setdefault("key", key if key is not None else "")
+            kwargs.pop("resource_id")
+            kwargs.setdefault("resource_id", "WDI")
         elif kwargs.get("resource_type") == Resource.dataflow:
             # Here we have no agency_id (/all/latest is allowed).
             # Unless set, it is added automatically, use url to avoid that.