def verify
raise ArgumentError, "usage with invalid value: #{@usage}" if @usage < 0 || @usage > 255
raise ArgumentError, "selector with invalid value: #{@selector}" if @selector < 0 || @selector > 255
raise ArgumentError, "matching_type with invalid value: #{@matching_type}" if @matching_type < 0 || @matching_type > 255
raise ArgumentError, "data with invalid value: #{@data}" if (@matching_type == 1 && @databin.bytesize != 32) || (@matching_type == 2 && @databin.bytesize != 64)
pkey if @matching_type == 0
end