You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: excel.rb
    path of file: ./repos/spreadsheet/lib/spreadsheet
    
    the code of the file until where you have to start completion: require 'spreadsheet'

##
# Spreadsheet::Excel Compatibility Layer.
# Drop-in replacement for Spreadsheet::Excel version <= 0.3.5.1
module Spreadsheet
  module Excel
    class ExcelCom
    
    def write_column row, col, data=nil, format=nil
      if data.is_a? Array
        data.each do |token|
          if token.is_a? Array
            write_row row, col, token, format
          else
            write row, col, token, format
          end
          row += 1
        end