anchor.diff:  }
   
   /**
  - * Instances of the class `SimpleStringLiteral` represent a string literal expression that
  - * does not contain any interpolations.
  + * A string literal expression that does not contain any interpolations.
    *
  - * <pre>
  - * simpleStringLiteral ::=
  - *     rawStringLiteral
  - *   | basicStringLiteral
  - *
  - * rawStringLiteral ::=
  - *     'r' basicStringLiteral
  - *
  - * simpleStringLiteral ::=
  - *     multiLineStringLiteral
  - *   | singleLineStringLiteral
  - *
  - * multiLineStringLiteral ::=
  - *     "'''" characters "'''"
  - *   | '"""' characters '"""'
  - *
  - * singleLineStringLiteral ::=
  - *     "'" characters "'"
  - *     '"' characters '"'
  - * </pre>
  + * > simpleStringLiteral ::=
  + * >     rawStringLiteral
  + * >   | basicStringLiteral
  + * >
  + * > rawStringLiteral ::=
  + * >     'r' basicStringLiteral
  + * >
  + * > simpleStringLiteral ::=
  + * >     multiLineStringLiteral
  + * >   | singleLineStringLiteral
  + * >
  + * > multiLineStringLiteral ::=
  + * >     "'''" characters "'''"
  + * >   | '"""' characters '"""'
  + * >
  + * > singleLineStringLiteral ::=
  + * >     "'" characters "'"
  + * >   | '"' characters '"'
    */
   class SimpleStringLiteral extends SingleStringLiteral {
     /**
  
positive.code:   Token keyword;
  
    /**
     * The expression computing the value to be returned, or `null` if no explicit value was
     * provided.
     */
    Expression _expression;
  
  
negative.code:   Token semicolon;
  
    /**
     * Initialize a newly created function body consisting of a block of
     * statements. The [keyword] can be `null` if the function body is not an
     * async function body.
     */
    ExpressionFunctionBody(this.keyword, this.functionDefinition,
        Expression expression, this.semicolon) {
  