message: TFLite should allow values of 0 for default_ranges_{min,max}.
diff: @@ -116,7 +116,8 @@ def _convert_model(flags):
  "tensors in order to map between names and "
  "values.".format(",".join(input_arrays)))
  converter.quantized_input_stats = dict(zip(input_arrays, quant_stats))
  - if flags.default_ranges_min and flags.default_ranges_max:
  + if (flags.default_ranges_min is not None) and (flags.default_ranges_max is
  + not None):
  converter.default_ranges_stats = (flags.default_ranges_min,
  flags.default_ranges_max)
  @@ -195,7 +196,7 @@ def _check_flags(flags, unparsed):
  raise ValueError("--std_dev_values, --mean_values must have the same "
  "number of items")
  - if bool(flags.default_ranges_min) != bool(flags.default_ranges_max):
  + if (flags.default_ranges_min is None) != (flags.default_ranges_max is None):
  raise ValueError("--default_ranges_min and --default_ranges_max must be "
  "used together")
  