How to use the py3status.formatter.Block function in py3status

def switch(self):
        """
        block has been split via | so we need to start a new block for that
        option and return it to the user.
        """
        base_block = self.base_block or self
        self.next_block = Block(
            self.parent, base_block=base_block, py3_wrapper=self.py3_wrapper
        )
        return self.next_block

or getattr(module, threshold_color_name, None)
                or getattr(module.py3, color_name.upper(), None)
            )
            if color == "hidden":
                return False, []

        text = ""
        out = []
        if isinstance(output, str):
            output = [output]

        # merge as much output as we can.
        first = True
        last_block = None
        for index, item in enumerate(output):
            is_block = isinstance(item, Block)
            if not is_block and item:
                last_block = None
            if isinstance(item, (str, bool, int, float, bytes)) or item is None:
                text += str(item)
                continue
            elif text:
                if not first and (text == "" or out and out[-1].get("color") == color):
                    out[-1]["full_text"] += text
                else:
                    part = {"full_text": text}
                    if color:
                        part["color"] = color
                    out.append(part)
                text = ""
            if isinstance(item, Composite):
                if color:

def build_block(self, format_string):
        """
        Parse the format string into blocks containing Literals, Placeholders
        etc that we can cache and reuse.
        """
        first_block = Block(None, py3_wrapper=self.py3_wrapper)
        block = first_block

        # Tokenize the format string and process them
        for token in self.tokens(format_string):
            value = token.group(0)
            if token.group("block_start"):
                # Create new block
                block = block.new_block()
            elif token.group("block_end"):
                # Close block setting any valid state as needed
                # and return to parent block to continue
                if not block.parent:
                    raise Exception("Too many `]`")
                block = block.parent
            elif token.group("switch"):
                # a new option has been created

def new_block(self):
        """
        create a new sub block to the current block and return it.
        the sub block is added to the current block.
        """
        child = Block(self, py3_wrapper=self.py3_wrapper)
        self.add(child)
        return child