Simple tool allowing me to print pretty boxes to the CLI

BoxCli.py

from __future__ import annotations


class BoxCli():
    def __init__(self: BoxCli, title: str = "", width: int = 0, lines: list[str] = [], _parent_width: int = 0) -> None:
        self.__width: int = (width if width > len(title) else len(title))+4
        self.title: str = title
        self.lines: list[str] = lines
        self._parent_width: int = _parent_width
        self._child: BoxCli | None = None

    def get_heading(self: BoxCli) -> str:
        heading = f" {self.title} ".center(self.width, "-")
        heading = "+" + heading[1:-1] + "+"
        if self._parent_width < self.width:
            heading = heading[:self._parent_width] + "+" + heading[self._parent_width+1:]
        return heading

    def add_line(self: BoxCli, line: str) -> None:
        self.lines.append(line)

    def add_lines(self: BoxCli, lines: list[str]) -> None:
        self.lines += lines

    def get_line(self: BoxCli, i) -> str:
        line: str = "| " + self.lines[i]
        line = line.ljust(self.width-2)
        line += " |"
        return line

    def get_footing(self: BoxCli) -> str:
        footing: str = "-"*self.width
        footing = "+" + footing[1:-1] + "+"
        return footing

    def print_heading(self: BoxCli) -> None:
        print(self.get_heading())

    def print_line(self: BoxCli, i) -> None:
        print(self.get_line(i))

    def print_lines(self: BoxCli) -> None:
        for index in range(len(self.lines)):
            self.print_line(index)

    def print_footing(self: BoxCli) -> None:
        print(self.get_footing(), end="\r")

    def print(self: BoxCli, with_children: bool = True) -> None:
        self.print_heading()
        self.print_lines()
        self.print_footing()
        if with_children and self._child:
            return self._child.print()

    def set_child(self: BoxCli, title: str = "", width: int = 0, lines: list[str] = []) -> BoxCli:
        self._child = BoxCli(title=title, width=width,
                             lines=lines, _parent_width=self.width-1)
        return self._child

    @property
    def width(self: BoxCli) -> int:
        return self.__width if self.__width > (new_width := len(max(self.lines, key=len, default=[0]))+4) else new_width


box: BoxCli = BoxCli("Hello, World!", lines=[
    "This is a test thing",
    "Really, I just wanna see how this looks"
])
child_box: BoxCli = box.set_child("Also this is a child!", lines=[
    "I think this is pretty cool (If I do say so myself)",
    "And I am always objectively right."
])
aborted_child_box: BoxCli = child_box.set_child("Your box is: Damn box", lines=[
    "Get it? It's the Uncanny joke (I don't get it)"
])

box.print(with_children=True)

Output:

+------------- Hello, World! -------------+
| This is a test thing                    |
| Really, I just wanna see how this looks |
+--------------- Also this is a child! ---+-----------+
| I think this is pretty cool (If I do say so myself) |
| And I am always objectively right.                  |
+------------ Your box is: Damn box -------------+----+
| Get it? It's the Uncanny joke (I don't get it) |
+------------------------------------------------+