RVC 3rd Edition - rot2 - import?

[xemjeff]

The book introduces python on page 13. It shows a basic command to create a 2d rotational matrix.
Again on page 34.

But nowhere do I see the required import statement. It's not clear where rot2() comes from. I don't find it in roboticstoolbox, or in spatialmath or numpy. I'm missing something obvious, but I don't see the obvious in the book either.

Would someone let me know what to import for rot2()?

Python 3.9.6 (default, Oct 18 2022, 12:41:40) 
[Clang 14.0.0 (clang-1400.0.29.202)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> R = rot2(0.3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'rot2' is not defined
>>> from roboticstoolbox import *
>>> R = rot2(0.3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'rot2' is not defined
>>> from spatialmath import *
>>> R = rot2(0.3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'rot2' is not defined
>>> 

I found it, after snooping around:

>>> from spatialmath.base.transforms2d import *
>>> rot2(0.3)
array([[ 0.95533649, -0.29552021],
       [ 0.29552021,  0.95533649]])
>>> 

Some of this information is in the book on page 79. It comes well after the introduction of the functions.
There is also a python notebook page that has more python preamble:

https://github.com/petercorke/RVC3-python/blob/main/notebooks/chap2.ipynb