def merge(into: Union[TOMLDocument, dict], update: Union[TOMLDocument, dict]):
    """Merges second dict into first recursively"""
    for key, val in update.items():
        if isinstance(into.get(key), dict) and isinstance(val, dict):
            merge(into[key], val)  # type: ignore[arg-type]
        else:
            into[key] = val
Merges second dict into first recursively
src/datachain/config.py