How to use the dfvfs.path.os_path_spec function in dfvfs

def setUp(self):
    """Sets up the needed objects used throughout the test."""
    self._resolver_context = context.Context()

    test_file = self._GetTestFilePath([])
    self._SkipIfPathNotExists(test_file)

    self._os_path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._os_file_system = os_file_system.OSFileSystem(self._resolver_context)

    # TODO: add RAW volume only test image.

    test_file = self._GetTestFilePath(['vsstest.qcow2'])
    self._SkipIfPathNotExists(test_file)

    path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._qcow_path_spec = qcow_path_spec.QCOWPathSpec(parent=path_spec)
    self._tsk_path_spec = tsk_path_spec.TSKPathSpec(
        location='/', parent=self._qcow_path_spec)

    self._tsk_file_system = tsk_file_system.TSKFileSystem(
        self._resolver_context)
    self._tsk_file_system.Open(self._tsk_path_spec)

def setUp(self):
    """Sets up the needed objects used throughout the test."""
    self._resolver_context = context.Context()
    test_file = self._GetTestFilePath(['blob.db'])
    self._SkipIfPathNotExists(test_file)

    path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._sqlite_blob_path_spec = sqlite_blob_path_spec.SQLiteBlobPathSpec(
        table_name='myblobs', column_name='blobs',
        row_condition=('name', '==', 'mmssms.db'), parent=path_spec)
    self._sqlite_blob_path_spec_2 = sqlite_blob_path_spec.SQLiteBlobPathSpec(
        table_name='myblobs', column_name='blobs',
        row_index=2, parent=path_spec)

def setUp(self):
    """Sets up the needed objects used throughout the test."""
    self._resolver_context = context.Context()
    test_file = self._GetTestFilePath(['vsstest.qcow2'])
    self._SkipIfPathNotExists(test_file)

    path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._qcow_path_spec = qcow_path_spec.QCOWPathSpec(parent=path_spec)
    self._ntfs_path_spec = ntfs_path_spec.NTFSPathSpec(
        location='\\', parent=self._qcow_path_spec)

    self._file_system = ntfs_file_system.NTFSFileSystem(self._resolver_context)
    self._file_system.Open(self._ntfs_path_spec)

def setUp(self):
    """Sets up the needed objects used throughout the test."""
    self._resolver_context = context.Context()
    test_file = self._GetTestFilePath(['syslog'])
    self._SkipIfPathNotExists(test_file)

    self._os_path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._data_range_path_spec = data_range_path_spec.DataRangePathSpec(
        range_offset=167, range_size=1080, parent=self._os_path_spec)

def setUp(self):
    """Sets up the needed objects used throughout the test."""
    super(QCOWFileTest, self).setUp()
    test_file = self._GetTestFilePath(['ext2.qcow2'])
    self._SkipIfPathNotExists(test_file)

    self._os_path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._qcow_path_spec = qcow_path_spec.QCOWPathSpec(
        parent=self._os_path_spec)

def setUp(self):
    """Sets up the needed objects used throughout the test."""
    self._resolver_context = context.Context()
    test_file = self._GetTestFilePath(['syslog.rc4'])
    self._SkipIfPathNotExists(test_file)

    path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._encrypted_stream_path_spec = (
        encrypted_stream_path_spec.EncryptedStreamPathSpec(
            encryption_method=definitions.ENCRYPTION_METHOD_RC4,
            parent=path_spec))
    resolver.Resolver.key_chain.SetCredential(
        self._encrypted_stream_path_spec, 'key', self._RC4_KEY)

def testReadlineWithEndOfFileTruncation(self):
    """Test the readline() function with specified size at end of file."""
    test_file = self._GetTestFilePath(['password.txt'])
    self._SkipIfPathNotExists(test_file)

    test_path_spec = os_path_spec.OSPathSpec(location=test_file)

    file_object = os_file_io.OSFile(self._resolver_context)
    file_object.open(test_path_spec)
    text_file_object = text_file.TextFile(file_object)

    line = text_file_object.readline(size=24)
    self.assertEqual(line, 'place,user,password\n')
    line = text_file_object.readline(size=24)
    self.assertEqual(line, 'bank,joesmith,superrich\n')
    line = text_file_object.readline(size=24)
    self.assertEqual(line, 'alarm system,-,1234\n')
    line = text_file_object.readline(size=24)
    self.assertEqual(line, 'treasure chest,-,1111\n')
    line = text_file_object.readline(size=30)
    self.assertEqual(line, 'uber secret laire,admin,admin\n')

def setUp(self):
    """Sets up the needed objects used throughout the test."""
    self._resolver_context = context.Context()
    test_file = self._GetTestFilePath(['vsstest.qcow2'])
    self._SkipIfPathNotExists(test_file)

    path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._qcow_path_spec = qcow_path_spec.QCOWPathSpec(parent=path_spec)
    self._vshadow_path_spec = vshadow_path_spec.VShadowPathSpec(
        location='/', parent=self._qcow_path_spec)

    self._file_system = vshadow_file_system.VShadowFileSystem(
        self._resolver_context)
    self._file_system.Open(self._vshadow_path_spec)

def setUp(self):
    """Sets up the needed objects used throughout the test."""
    self._resolver_context = context.Context()
    test_file = self._GetTestFilePath(['syslog.base64'])
    self._SkipIfPathNotExists(test_file)

    path_spec = os_path_spec.OSPathSpec(location=test_file)
    self._encoded_stream_path_spec = (
        encoded_stream_path_spec.EncodedStreamPathSpec(
            encoding_method=definitions.ENCODING_METHOD_BASE64,
            parent=path_spec))

    self._file_system = (
        encoded_stream_file_system.EncodedStreamFileSystem(
            self._resolver_context))
    self._file_system.Open(self._encoded_stream_path_spec)

self.assertIsNotNone(file_entry)
    self.assertEqual(file_entry.name, 'syslog')

    path_spec = zip_path_spec.ZipPathSpec(
        location='/bogus', parent=self._os_path_spec)
    file_entry = file_system.GetFileEntryByPathSpec(path_spec)

    self.assertIsNone(file_entry)

    file_system.Close()

    # Test on a tar file that has missing directory entries.
    test_file = self._GetTestFilePath(['missing_directory_entries.zip'])
    self._SkipIfPathNotExists(test_file)

    test_file_path_spec = os_path_spec.OSPathSpec(location=test_file)
    path_spec = zip_path_spec.ZipPathSpec(
        location='/', parent=test_file_path_spec)

    file_system = zip_file_system.ZipFileSystem(self._resolver_context)
    self.assertIsNotNone(file_system)
    file_system.Open(path_spec)

    path_spec = zip_path_spec.ZipPathSpec(
        location='/folder', parent=test_file_path_spec)
    file_entry = file_system.GetFileEntryByPathSpec(path_spec)
    self.assertIsNotNone(file_entry)
    self.assertTrue(file_entry.IsVirtual())
    self.assertEqual(file_entry.name, 'folder')

    path_spec = zip_path_spec.ZipPathSpec(
        location='/folder/syslog', parent=test_file_path_spec)