def cost_of block
      assumes = block.select{ |s| s.is_a?(AssumeStatement)}
      cost = assumes.inject(0) do |acc, stmt|
        if values = stmt.get_attribute(:'smack.InstTimingCost.Int64')
          acc += values.first.show.to_i
        end
        acc
      end

      return cost
    end
def cost_of block
      assumes = block.select{ |s| s.is_a?(AssumeStatement)}
      cost = assumes.inject(0) do |acc, stmt|
        if values = stmt.get_attribute(:'smack.InstTimingCost.Int64')
          acc += values.first.show.to_i
        end
        acc
      end

      return cost
    end
Iterates over timing annotations of a block and sums them up.