---------------------- I'm sorry, but the information extracts provided do not contain the specific details about the source code of the VectorStore module from llama_index.core or how to adjust context_window.
However, you can find examples of how to use VectorStoreIndex and other classes from llama_index.core in the SimpleIndexDemo notebook () on GitHub.
For more detailed information, I would recommend checking the official documentation or the source code directly on the LlamaIndex GitHub repository (). ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------