Chunks after `batch_size` treated as non-existant

### Checked other resources - [x] This is a bug, not a usage question. For questions, please use the LangChain Forum (https://forum.langchain.com/). - [x] I added a clear and descriptive title that summarizes this issue. - [x] I used the GitHub search to find a similar question and didn't find it. - [x] I am sure that this is a bug in LangChain rather than my code. - [x] The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package). - [x] I read what a minimal reproducible example is (https://stackoverflow.com/help/minimal-reproducible-example). - [x] I posted a self-contained, minimal, reproducible example. A maintainer can copy it and run it AS IS. ### Example Code Install deps: ```bash pip install -U aiosqlite greenlet langchain langchain_community langchain_core langchain_text_splitters langchain_qdrant qdrant_client ``` Run code: ``` from langchain import indexes from langchain_community.embeddings import FakeEmbeddings from langchain_core.documents import Document from langchain_text_splitters import RecursiveCharacterTextSplitter from langchain_qdrant import QdrantVectorStore from qdrant_client import QdrantClient from qdrant_client.http.models import Distance, VectorParams client = QdrantClient(":memory:") client.create_collection( collection_name="some_collection", vectors_config=VectorParams(size=256, distance=Distance.COSINE), ) store = QdrantVectorStore( client=client, collection_name="some_collection", embedding=FakeEmbeddings(size=256), ) manager = indexes.SQLRecordManager("index", db_url="sqlite+aiosqlite:///db.sqlite", async_mode=True) await manager.acreate_schema() splitter = RecursiveCharacterTextSplitter(chunk_size=10, chunk_overlap=0) document = Document( page_content="\n".join(map(str, range(100))), metadata={ "source": "some_url", "title": "some_title", }, ) chunks = await splitter.atransform_documents([document]) for _ in range(5): stats =…