use firecrawl::FirecrawlApp;use std::error::Error; #[tokio::main]async fn main() -> Result<(), Box<dyn Error>> {    // Get API URL from environment    let api_url = std::env::var("FIRECRAWL_API_URL")        .expect("Please set the FIRECRAWL_API_URL environment variable");     // Create the FirecrawlApp instance    let firecrawl = FirecrawlApp::new_selfhosted(api_url, None::<&str>)?;     // Start a crawl job that will likely have some errors (invalid URL format)    println!("Starting a crawl job...");    let crawl_response = firecrawl        .crawl_url_async("https://no-wer-agg.invalid", None)        .await?;    println!("Crawl job started with ID: {}", crawl_response.id);     println!("Let it do it's thing...");    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;     // Check the crawl errors    println!("Checking for crawl errors...");    match firecrawl.check_crawl_errors(&crawl_response.id).await {        Ok(error_response) => {            println!("Crawl errors response:");            println!("  Number of errors: {}", error_response.errors.len());             if !error_response.errors.is_empty() {                println!("\nDetailed errors:");                for (i, error) in error_response.errors.iter().enumerate() {                    println!("Error #{}", i + 1);                    println!("  ID: {}", error.id);                    if let Some(timestamp) = &error.timestamp {                        println!("  Timestamp: {}", timestamp);                    }                    println!("  URL: {}", error.url);                    println!("  Error: {}", error.error);                }            }             println!(                "\nRobots.txt blocked URLs: {}",                error_response.robots_blocked.len()            );            for (i, url) in error_response.robots_blocked.iter().enumerate() {                println!("  {}. {}", i + 1, url);            }        }        Err(e) => {            println!("Failed to check crawl errors: {}", e);        }    }    let cancel = firecrawl.cancel_crawl(&crawl_response.id).await?;    println!("Cancel: {}", cancel.status);     Ok(())}