csv / CSV / CSV::Reader / CSV::StringReader / CSV::IOReader /CSV::Writer / CSV::BasicWriter
CSV::Writer.generate(str_or_writable[, fs = ','[, rs = nil]]) { ... }
CSV::Writer.create(str_or_writable[, fs = ','[, rs = nil]])
CSV::Writer#<<(row)
CSV::Writer#add_row(row)
CSV::Writer#close