def +(other)
      self.class.new(*(
        [
          usage,
          processor_id == other.processor_id ? processor_id : 0,
        ] +
        values_at(2..-3).zip(other.values_at(2..-3)).map { |x, y| x + y } +
        [
          [ start_at, other.start_at ].min,
          [ stop_at, other.stop_at ].max
        ])
      )
    end
def +(other)
      self.class.new(*(
        [
          usage,
          processor_id == other.processor_id ? processor_id : 0,
        ] +
        values_at(2..-3).zip(other.values_at(2..-3)).map { |x, y| x + y } +
        [
          [ start_at, other.start_at ].min,
          [ stop_at, other.stop_at ].max
        ])
      )
    end
Add this CPU::Usage instance to the other and return a resulting sum object.