private String createInvalidNumberString(int startPosition, String message) {
        String lexeme = sliceFrom(startPosition);
        return String.format("Invalid number '%s': %s", lexeme, message);
    }
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