How to Async Grayscale Image in D - Code Snippet

// Task: Async Grayscale Image
// Language: D

void async_grayscale_image() {
    // Implementation for Async Grayscale Image
    auto result = ...; // Initialize variable
    // TODO: Implement core logic here
    // Step 1: Prepare data
    // Step 2: Process Async Grayscale Image
    writeln("Done");
}