message: nydus-test: give nydus-image --chunk-size parameter
diff: @@ -363,6 +363,7 @@ class RafsImage(LinuxCommand):
  from_stargz=False,
  fs_version=None,
  disable_check=False,
  + chunk_size=None,
  ) -> "RafsImage":
  """
  :layers: Create an image on top of an existed one
  @@ -390,6 +391,9 @@ class RafsImage(LinuxCommand):
  if self.compressor is not None:
  self.set_param("compressor", str(self.compressor))
  + if chunk_size is not None:
  + self.set_param("chunk-size", str(hex(chunk_size)))
  +
  builder_output_json = tempfile.NamedTemporaryFile("w+", suffix="output.json")
  self.set_param("output-json", builder_output_json.name)
  builder_output_json.flush()
  