Adds the doc for asNondeterministic for wrapped UDF function

Author: HyukjinKwon

python/pyspark/sql/tests.py

@@ -413,6 +413,7 @@ def test_nondeterministic_udf2(self):
         pydoc.render_doc(udf(lambda: random.randint(6, 6), IntegerType()))
         pydoc.render_doc(random_udf)
         pydoc.render_doc(random_udf1)
+        pydoc.render_doc(udf(lambda x: x).asNondeterministic)
 
     def test_nondeterministic_udf_in_aggregate(self):
         from pyspark.sql.functions import udf, sum

python/pyspark/sql/udf.py

@@ -169,8 +169,8 @@ def wrapper(*args):
         wrapper.returnType = self.returnType
         wrapper.evalType = self.evalType
         wrapper.deterministic = self.deterministic
-        wrapper.asNondeterministic = lambda: self.asNondeterministic()._wrapped()
-
+        wrapper.asNondeterministic = functools.wraps(
+            self.asNondeterministic)(lambda: self.asNondeterministic()._wrapped())
         return wrapper
 
     def asNondeterministic(self):