code: def test_blob(self):
      with open(JPEG_FILE, "rb") as f:
          blob = f.read()
      gv = pyvips.GValue()
      gv.set_type(pyvips.GValue.blob_type)
      gv.set(blob)
      value = gv.get()
      assert value == blob
  
file_path: pyvips/tests/test_gvalue.py
imports: import pytest
  import pyvips
  from helpers import JPEG_FILE, assert_almost_equal_objects
label_desc: Use image node_id 12 for calling the TestGValue obj's underlying member method code with example usage: obj.test_blob() without return types