private Token parseLiteral() {
        int currentLine = line;
        int currentColumn = column;
        currentlyParsingLiteral = true;
        expect('`');
        ws();
        Object value = parseJsonValue();
        ws();
        expect('`');
        currentlyParsingLiteral = false;
        LiteralExpression expression = new LiteralExpression(value, currentLine, currentColumn);
        return new Token(TokenType.LITERAL, expression, currentLine, currentColumn);
    }
Gets a slice of the expression starting from the given 0-based
character position, read all the way through to the current
position of the parser.

@param start Position to slice from, ending at the current position.
@return Returns the slice of the expression from {@code start} to {@link #position}.
smithy-jmespath/src/main/java/software/amazon/smithy/jmespath/Lexer.java