## Description of bug / unexpected behavior When attempting to use `get_number_mobjects()` on a `NumberLine` object, I encountered the following error: ``` AttributeError: NumberLine object has no attribute 'default_numbers_to_display' ``` It seems like the method `get_number_mobjects()` internally calls `self.default_numbers_to_display()`, but this method is either missing or no longer available in the current implementation of `NumberLine`. ## Expected behavior Calling `get_number_mobjects()` with no arguments should use default numbers (e.g., from `x_range`) to generate label mobjects. ## How to reproduce the issue 1. Create a `NumberLine` object. 2. Call `get_number_mobjects()` without passing any explicit numbers. 3. Run the scene. <details><summary>Code for reproducing the problem</summary> ```py from manim import * class IntroductionToComplexNumbers(Scene): def construct(self): # Create real number line real_number_line = NumberLine( x_range=[-5, 5, 1], length=10, include_tip=False, ) real_number_line_labels = real_number_line.get_number_mobjects() self.add(real_number_line, *real_number_line_labels) ``` </details> ## Logs <details><summary>Terminal output</summary> <!-- Add "-v DEBUG" when calling manim to generate more detailed logs --> [Logs](https://pastebin.com/bW1jRatq) <!-- Insert screenshots here (only when absolutely necessary, we prefer copy/pasted output!) --> </details> ## System specifications <details><summary>System Details</summary> ``` Environment * **OS:** Windows 11 * **Manim version:** (e.g., v0.19.0) * **Python version:** (e.g., 3.10) * **Installation:** pip ``` </details>