...The crawler supports the IPFS, Filecoin, Polkadot, Kusama, Rococo, Westend networks and more. The crawler can store its results as JSON documents or in a postgres database - the --dry-run flag prevents it from doing either. Nebula will print a summary of the crawl at the end instead. A crawl takes ~5-10 min depending on your internet connection. You can also specify the network you want to crawl by appending, e.g., --network FILECOIN and limit the number of peers to crawl by providing the --limit flag.