Adding default configuration to reader

udpos.py

@@ -239,7 +239,7 @@ class Udpos(datasets.GeneratorBasedBuilder):
     for lang in _URLS:
         datasets.BuilderConfig(name=lang, version=VERSION, description="Split corresponding to language "+lang)
 
-    # DEFAULT_CONFIG_NAME = "first_domain"  # It's not mandatory to have a default configuration. Just use one if it make sense.
+    DEFAULT_CONFIG_NAME = "en"  # It's not mandatory to have a default configuration. Just use one if it make sense.
 
     def _info(self):
         features = datasets.Features(