public void Process()
{
string basename = _context.Basename;
Pipeline pipeline = _context.GetPipeline();
var page = pipeline.Input($"{_context.InputFilePrefix}.pdf")
.Page(1)
.ParsePdf <ProcessPdfText>()
.ParseBlock <ExtractDouHeaderInfo>();
var extract = page.CreateInstance <ExtractDouHeaderInfo>();
var infoStats = extract.InfoStats;
string content = infoStats.ToString();
var filename = _context.CreateGlobalInstance <InjectFilename>();
filename.Filename = _context.Basename;
filename.InfoStats = infoStats;
_context.WriteFile("header", $"{_context.OutputFilePrefix}-header.txt", content);
}