def _create_source(self, data):
     source = LineSource(self._create_file_with_data(data))
     # By performing initial splitting, we can get a source for a single file.
     # This source, that uses OffsetRangeTracker, is better for testing purposes,
     # than using the original source for a file-pattern.
     for bundle in source.split(float('inf')):
         return bundle.source
 def _create_source(self, data):
   source = LineSource(self._create_file_with_data(data))
   # By performing initial splitting, we can get a source for a single file.
   # This source, that uses OffsetRangeTracker, is better for testing purposes,
   # than using the original source for a file-pattern.
   for bundle in source.split(float('inf')):
     return bundle.source