[DefaultMember("Item")]
public class MergedCellCollection : WorksheetElement 

using( var workbook = Workbook.Create( "MergedCellCollection.xlsx" ) ) 
  { 
    // Gets the first Worksheet; a Workbook always contains at least 1 Worksheet. 
    var worksheet = workbook.Worksheets[ 0 ]; 

    // Merges Cells A1 to B2. 
    var mergedCells = worksheet.MergedCells.Add( "A1", "B2" ); 
    var cellCount = mergedCells.Count; 

    // Merges the Cells in the D4 to D8 range. 
    var cellRange = worksheet.Cells[ "D4", "D8" ]; 
    cellRange.MergeCells(); 

    // Saves Workbook to disk; 
    workbook.Save(); 
  }