+ subtract_by_key
+ subtract_by_key

ondra-m/ruby-spark,tomz/ruby-spark,ondra-m/ruby-spark,tomz/ruby-spark,ondra-m/ruby-spark,ondra-m/ruby-spark,tomz/ruby-spark,tomz/ruby-spark,tomz/ruby-spark,tomz/ruby-spark,ondra-m/ruby-spark,ondra-m/ruby-spark