docs: function(context: ParserContext): ?Token {
      const delimiter = context.reader.peek();
      if (delimiter !== '"' && delimiter !== "'") return null;
      if (!isInsideOpenBracket(context)) return null;
  
      // read until the delimiter
      let stringValue = context.reader.read();
      while (!context.reader.isEOF()) {
        const next = context.reader.read();
        stringValue += next;
  
        if (next === delimiter) break;
      }
  
      return context.createToken("string", stringValue);
    }