How to use the parso.python_bytes_to_unicode function in parso

dct = {}
    current_path = object()
    new_lines = old_lines = None
    for name in order:
        if name.in_builtin_module():
            continue
        if current_path != name.module_path:
            current_path = name.module_path

            process(current_path, old_lines, new_lines)
            if current_path is not None:
                # None means take the source that is a normal param.
                with open(current_path) as f:
                    source = f.read()

            new_lines = split_lines(python_bytes_to_unicode(source))
            old_lines = new_lines[:]

        nr, indent = name.line, name.column
        line = new_lines[nr - 1]
        new_lines[nr - 1] = line[:indent] + replace_str + \
            line[indent + len(name.name):]
    process(current_path, old_lines, new_lines)
    return dct

dct = {}
    current_path = object()
    new_lines = old_lines = None
    for name in order:
        if name.in_builtin_module():
            continue
        if current_path != name.module_path:
            current_path = name.module_path

            process(current_path, old_lines, new_lines)
            if current_path is not None:
                # None means take the source that is a normal param.
                with open(current_path) as f:
                    source = f.read()

            new_lines = split_lines(python_bytes_to_unicode(source))
            old_lines = new_lines[:]

        nr, indent = name.line, name.column
        line = new_lines[nr - 1]
        new_lines[nr - 1] = line[:indent] + replace_str + \
            line[indent + len(name.name):]
    process(current_path, old_lines, new_lines)
    return dct

def inline(script):
    """
    :type script: api.Script
    """
    new_lines = split_lines(python_bytes_to_unicode(script.source))

    dct = {}

    definitions = script.goto_assignments()
    assert len(definitions) == 1
    stmt = definitions[0]._definition
    usages = script.usages()
    inlines = [r for r in usages
               if not stmt.start_pos <= (r.line, r.column) <= stmt.end_pos]
    inlines = sorted(inlines, key=lambda x: (x.module_path, x.line, x.column),
                     reverse=True)
    expression_list = stmt.expression_list()
    # don't allow multiline refactorings for now.
    assert stmt.start_pos[0] == stmt.end_pos[0]
    index = stmt.start_pos[0] - 1

dct = {}
    current_path = object()
    new_lines = old_lines = None
    for name in order:
        if name.in_builtin_module():
            continue
        if current_path != name.module_path:
            current_path = name.module_path

            process(current_path, old_lines, new_lines)
            if current_path is not None:
                # None means take the source that is a normal param.
                with open(current_path) as f:
                    source = f.read()

            new_lines = split_lines(python_bytes_to_unicode(source))
            old_lines = new_lines[:]

        nr, indent = name.line, name.column
        line = new_lines[nr - 1]
        new_lines[nr - 1] = line[:indent] + replace_str + \
            line[indent + len(name.name):]
    process(current_path, old_lines, new_lines)
    return dct

def extract(script, new_name):
    """ The `args` / `kwargs` params are the same as in `api.Script`.
    :param operation: The refactoring operation to execute.
    :type operation: str
    :type source: str
    :return: list of changed lines/changed files
    """
    new_lines = split_lines(python_bytes_to_unicode(script.source))
    old_lines = new_lines[:]

    user_stmt = script._parser.user_stmt()

    # TODO care for multiline extracts
    dct = {}
    if user_stmt:
        pos = script._pos
        line_index = pos[0] - 1
        arr, index = helpers.array_for_pos(user_stmt, pos)
        if arr is not None:
            start_pos = arr[index].start_pos
            end_pos = arr[index].end_pos

            # take full line if the start line is different from end line
            e = end_pos[1] if end_pos[0] == start_pos[0] else None

def extract(script, new_name):
    """ The `args` / `kwargs` params are the same as in `api.Script`.
    :param operation: The refactoring operation to execute.
    :type operation: str
    :type source: str
    :return: list of changed lines/changed files
    """
    new_lines = split_lines(python_bytes_to_unicode(script.source))
    old_lines = new_lines[:]

    user_stmt = script._parser.user_stmt()

    # TODO care for multi-line extracts
    dct = {}
    if user_stmt:
        pos = script._pos
        line_index = pos[0] - 1
        # Be careful here. 'array_for_pos' does not exist in 'helpers'.
        arr, index = helpers.array_for_pos(user_stmt, pos)
        if arr is not None:
            start_pos = arr[index].start_pos
            end_pos = arr[index].end_pos

            # take full line if the start line is different from end line

def parse_and_get_code(self, code=None, path=None, encoding='utf-8',
                           use_latest_grammar=False, file_io=None, **kwargs):
        if code is None:
            if file_io is None:
                file_io = FileIO(path)
            code = file_io.read()
        # We cannot just use parso, because it doesn't use errors='replace'.
        code = python_bytes_to_unicode(code, encoding=encoding, errors='replace')

        if len(code) > settings._cropped_file_size:
            code = code[:settings._cropped_file_size]

        grammar = self.latest_grammar if use_latest_grammar else self.grammar
        return grammar.parse(code=code, path=path, file_io=file_io, **kwargs), code