twig function bem() removes attributes of parent twig file

[ndf]

What you did:

We have a hierarchy of templates.

1. In side the top-template (in our case webform.html.twig) we call the child template with an include like this {% include "@atoms/02-text/00-headings/_heading.twig".
2. Inside the child template function bem() is called: {{ bem(heading_base_class, (heading_modifiers), heading_blockname) }}
3. Further down in the parent template, after the include, {{attributes}} is rendered. In this case it must print the form attributes like id, class, but also form-specific attributes like method and action.

What happened:
The function bem() in bem.function.php removes/resets the attribute function in the following block of code:

// Remove the attribute from context so it doesn't trickle down to
// includes.
$context['attributes']->removeAttribute($key);

The effect is that {{attributes}} is empty.
If I uncomment above, then bem() prints the attributes of the webform in the _heading.twig. Also not good. But the good part is that the webform itself can print its attributes. (In this example the attribute-list is printed 2 times in the webform and the heading template).

Reproduction repository (if necessary):

Problem description:
How can this problem be avoided?

Suggested solution:
Either that the bem() function resolves this automatically,
or by adding some documentation how the bem() function must be called to avoid this problem.

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[ModulesUnraveled]

@callinmullaney I wonder if this is related to the issue with views you mentioned you were working on