code: def test_find_private_section_fake():
      # Make and test fake datasets
      ds = pydicom.dataset.Dataset({})
      assert fps(ds, 0x11, "some section") is None
      ds.add_new((0x11, 0x10), "LO", b"some section")
      assert fps(ds, 0x11, "some section") == 0x1000
      ds.add_new((0x11, 0x11), "LO", b"another section")
      ds.add_new((0x11, 0x12), "LO", b"third section")
      assert fps(ds, 0x11, "third section") == 0x1200
      # Technically incorrect 'OB' is acceptable for VM (should be 'LO')
      ds.add_new((0x11, 0x12), "OB", b"third section")
      assert fps(ds, 0x11, "third section") == 0x1200
      # Anything else not acceptable
      ds.add_new((0x11, 0x12), "PN", b"third section")
      assert fps(ds, 0x11, "third section") is None
      # The input (DICOM value) can be a string insteal of bytes
      ds.add_new((0x11, 0x12), "LO", "third section")
      assert fps(ds, 0x11, "third section") == 0x1200
      # Search can be bytes as well as string
      ds.add_new((0x11, 0x12), "LO", b"third section")
      assert fps(ds, 0x11, b"third section") == 0x1200
      # Search with string or bytes must be exact
      assert fps(ds, 0x11, b"third sectio") is None
      assert fps(ds, 0x11, "hird sectio") is None
      # The search can be a regexp
      assert fps(ds, 0x11, re.compile(r"third\Wsectio[nN]")) == 0x1200
      # No match -> None
      assert fps(ds, 0x11, re.compile(r"not third\Wsectio[nN]")) is None
      # If there are gaps in the sequence before the one we want, that is OK
      ds.add_new((0x11, 0x13), "LO", b"near section")
      assert fps(ds, 0x11, "near section") == 0x1300
      ds.add_new((0x11, 0x15), "LO", b"far section")
      assert fps(ds, 0x11, "far section") == 0x1500
      # More than one match - find the first.
      assert (
          fps(ds, 0x11, re.compile("(another|third) section")) == 0x1100
      )
      # The signalling element number must be <= 0xFF
      ds = pydicom.dataset.Dataset({})
      ds.add_new((0x11, 0xFF), "LO", b"some section")
      assert fps(ds, 0x11, "some section") == 0xFF00
      ds = pydicom.dataset.Dataset({})
      ds.add_new((0x11, 0x100), "LO", b"some section")
      assert fps(ds, 0x11, "some section") is None
  
imports: import re
  from nibabel.optpkg import optional_package
  from ..utils import find_private_section
  from .test_dicomwrappers import DATA, DATA_PHILIPS
label_desc: Use image node_id 2 for calling a global function with example usage: test_find_private_section_fake() without return types