def _postprocess_chunks(self, chunks: List[str]) -> List[str]:
        """
        Post-process chunks.
        Remove whitespace only chunks and remove leading and trailing whitespace.
        """
        new_chunks = []
        for chunk in chunks:
            stripped_chunk = chunk.strip()
            if stripped_chunk == "":
                continue
            new_chunks.append(stripped_chunk)
        return new_chunks

        Post-process chunks.
        Remove whitespace only chunks and remove leading and trailing whitespace.
        
llama-index-core/llama_index/core/node_parser/text/sentence.py