def merge(target)
      start, stop = if target.is_a?(String)
                      [self.r, target]
                    elsif(target.is_a?(Cell))
                      Axlsx.sort_cells([self, target]).map { |c| c.r }
                    end
      self.row.worksheet.merge_cells "#{start}:#{stop}" unless stop.nil?
    end
def merge(target)
      start, stop = if target.is_a?(String)
                      [self.r, target]
                    elsif(target.is_a?(Cell))
                      Axlsx.sort_cells([self, target]).map { |c| c.r }
                    end
      self.row.worksheet.merge_cells "#{start}:#{stop}" unless stop.nil?
    end
Merges all the cells in a range created between this cell and the cell or string name for a cell  provided
 @see worksheet.merge_cells
 @param [Cell, String] target The last cell, or str ref for the cell in the merge range