> require('xlsx').readFile('merge_cells.xlsx').Sheets.Merge['!merges']
[ { s: { c: 0, r: 0 }, e: { c: 1, r: 1 } },  // <-- The cell A1 represents the range A1:B2
  { s: { c: 2, r: 0 }, e: { c: 2, r: 1 } },  // <-- The cell C1 represents the range C1:C2
  { s: { c: 0, r: 2 }, e: { c: 1, r: 2 } },  // <-- The cell A3 represents the range A3:B3
  { s: { c: 3, r: 0 }, e: { c: 3, r: 1 } },  // <-- The cell D1 represents the range D1:D2
  { s: { c: 0, r: 3 }, e: { c: 1, r: 3 } } ] // <-- The cell A4 represents the range A4:B4