def build_columns(header)
      columns = header.each_with_index.map do |header_column, index|
        convert_column(header_column, index).tap do |column|
          maybe_raise_missing_column!(column)
        end
      end

      @deduplicator.call(columns)
    end
def build_columns(header)
      columns = header.each_with_index.map do |header_column, index|
        convert_column(header_column, index).tap do |column|
          maybe_raise_missing_column!(column)
        end
      end

      @deduplicator.call(columns)
    end
Convert original header
 @param [Array<String>] header the original header
 @return [Array<String>] converted columns