anchor.diff:    Returns whether a [mixin][] named `$name` exists.
   
     [mixin]: ../at-rules/mixin
  -  
  +
     If `$module` is `null`, this returns whether a mixin named `$name` without a
     namespace exists. Otherwise, `$module` must be a string matching the namespace
     of a [`@use` rule][] in the current file, in which case this returns whether
  
positive.code: 
    [map function]: map
  
    <% example(autogen_css: false) do %> 
      @debug meta.type-of(10px); // number
      @debug meta.type-of(10px 20px 30px); // list
      @debug meta.type-of(()); // list
  
negative.code:             'inspect($value)',
              returns: 'unquoted string' do %>
    Returns a string representation of `$value`.
  
    Returns a representation of *any* Sass value, not just those that can be
    represented in CSS. As such, its return value is not guaranteed to be valid
    CSS.
  