The span around this always gets stripped.
    
    
      Content in a span only if foo was not defined.
    
    This is a literal dolars sign before
    not_a_var: $$not_a_var
    
      $a
    
    
      
        
          - $x is divisible by 3
- 
            ${x} is not divisible by 3,
            
              but it is divisible by ${y}!
            
          
${value_of('somevar', 'somevar is not set')}
    ${Markup('1234&')}
    
      
        
          ${i} divides by 3
        
        
          ${i} is not a friend of 3
        
        
          ${i} aspires to be a number that divides by 3
        
      
    
    
    ${_('')}