Update internals.py

Author: vmalaviya-splunk

splunklib/searchcommands/internals.py

@@ -595,7 +595,7 @@ def _write_record(self, record):
 
         if fieldnames is None:
             self.custom_fields |= set(record.keys())
-            self._fieldnames = fieldnames = [*self.custom_fields]
+            self._fieldnames = fieldnames = list(self.custom_fields)
             value_list = imap(lambda fn: (str(fn), str('__mv_') + str(fn)), fieldnames)
             self._writerow(list(chain.from_iterable(value_list)))