def format_data
      formatted_rows = []
      @data.each do |row|
        values = []
        row.each_with_index do |entry,index|
          values << Gvis::DataCell.new(entry, @column_types.to_a[index][1]).to_js
        end
        rowstring = "[#{values.join(", ")}]"
        formatted_rows << rowstring
      end
      "[#{formatted_rows.join(', ')}]"
    end
def format_data
      formatted_rows = []
      @data.each do |row|
        values = []
        row.each_with_index do |entry,index|
          values << Gvis::DataCell.new(entry, @column_types.to_a[index][1]).to_js
        end
        rowstring = "[#{values.join(", ")}]"
        formatted_rows << rowstring
      end
      "[#{formatted_rows.join(', ')}]"
    end
Outputs the data within this table as a javascript array ready for use by google.visualization.DataTable
 This is where conversions of ruby date objects to javascript Date objects and escaping strings, and formatting options is done
 @return [String] a javascript array with the first row defining the table, and subsequent rows holding the table's data