code: def mutate_row(row, mutations)
        mutations = mutations.map { |k,v| Apache::Hadoop::Hbase::Thrift::Mutation.new(:column => k, :value => v, :isDelete => v.nil?) }
        call :mutateRow, row, mutations
      end
docs: mutations is a key / value pair to insert / update for the given row
   the keys are in the form "family:column"