Retrieve metadata in USDZ

Hey folks,

I have entered "Extras" in the GLTF file and the conversion tool adds following metadata to USDA and USDZ file.

#usda 1.0
(
  customLayerData = {
  string creator = "gltf2usd v0.2.0"
  string gltf_extras_alignment = "vertical"
  string gltf_extras_test_property = "test_value"
  string gltf_generator = "FBX2glTF v0.9.7"
  string gltf_version = "2.0"
  }
)

I have been poking around trying to find out how to extract this customLayerData from USDZ file but I am stuck. Anyone have any luck with stuff like this?

Much appreciated!!