# File lib/ttfunk/table/kern/format0.rb, line 12
        def initialize(attributes={})
          @attributes = attributes

          num_pairs, search_range, entry_selector, range_shift, *pairs =
            attributes.delete(:data).unpack("n*")

          @pairs = {}
          num_pairs.times do |i|
            break if i*3+2 > pairs.length # sanity check, in case there's a bad length somewhere
            left = pairs[i*3]
            right = pairs[i*3+1]
            value = to_signed(pairs[i*3+2])
            @pairs[[left, right]] = value
          end
        end