anchor.diff:    ;
   
   throw_stmt
  -  : THROW (test (',' test (',' test))?)?
  +  : THROW test?
     ;
   
   // URLs refer to directory structure within sandbox or component, or to
  
positive.code:   ;
  
  assert_stmt
    : ASSERT test (',' test)?
    ;
  
  del_stmt
    : DEL exprlist
    ;
  
  pass_stmt
  
negative.code: OR: 'or';
  NOT: 'not';
  ASSERT: 'assert';
  STUB: 'stub';
  CONTINUE: 'continue';
  THROW: 'throw';
  FUNC: 'func';
  PASS: 'pass';