multiquery

type Config struct {
	// Rewrite
	// 1. set the following fields to use llm to generate multi queries
	// 	a. chat model, required
	RewriteLLM model.ChatModel
	//	b. prompt llm to generate multi queries, we provide default template so you can leave this field blank
	RewriteTemplate prompt.ChatTemplate
	//	c. origin query variable of your custom template, it can be empty if you use default template
	QueryVar string
	//	d. parser llm output to queries, split content using "\n" by default
	LLMOutputParser func(context.Context, *schema.Message) ([]string, error)
	// 2. set RewriteHandler to provide custom query generation logic, possibly without a ChatModel. If this field is set, it takes precedence over other configurations above
	RewriteHandler func(ctx context.Context, query string) ([]string, error)
	// limit max queries num that Rewrite generates, and excess queries will be truncated, 5 by default
	MaxQueriesNum int

	// Origin Retriever
	OrigRetriever retriever.Retriever

	// fusion docs recalled from multi retrievers, remove dup based on document id by default
	FusionFunc func(ctx context.Context, docs [][]*schema.Document) ([]*schema.Document, error)
}