unnittestexample.cs

public class PdfGenerator
{
    public async Task GeneratePdfAsync(string htmlContent)
    {
        // generate PDF from HTML content
    }
}

public class MyClass
{
    private readonly PdfGenerator _pdfGenerator;

    public MyClass(PdfGenerator pdfGenerator)
    {
        _pdfGenerator = pdfGenerator;
    }

    public async Task GeneratePdf(string htmlContent)
    {
        await _pdfGenerator.GeneratePdfAsync(htmlContent);
    }
}