public void TestTemplateMethod()
{
var excelExporter = new ExcelExporter();
excelExporter.ExportFormattedData();
// OUTPUT: Reading data from external source.
// OUTPUT: Formatting data.
// OUTPUT: Exporting data to Excel file.
var pdfExporter = new PdfExporter();
pdfExporter.ExportFormattedData();
// OUTPUT: Reading data from external source.
// OUTPUT: Formatting data.
// OUTPUT: Exporting data to PDF file.
}