anchor.diff:      | platformModifier) NL*
       ;
   
  +typeModifiers
  +    : typeModifier+
  +    ;
  +
  +typeModifier
  +    : annotation | 'suspend' NL*
  +    ;
  +
   classModifier
       : 'enum'
       | 'sealed'
  
positive.code: varianceModifier
      : 'in'
      | 'out'
      ;
  
  functionModifier
  
negative.code:     | SUPER_AT
      ;
  
  ifExpression
      : 'if' NL* '(' NL* expression NL* ')' NL* (controlStructureBody | ';')
      | 'if' NL* '(' NL* expression NL* ')' NL* controlStructureBody? NL* ';'? NL* 'else' NL* (controlStructureBody | ';')
      ;
  
  whenExpression
  