private List<Path> normalizePathsInCommandLineProperties(final String propertyName, final boolean multi) {
        if (!this.commandLineProperties.containsKey(propertyName)) {
            return Collections.unmodifiableList(new ArrayList<Path>());
        }
        final String property = this.commandLineProperties.getProperty(propertyName);
        if (property == null || property.isEmpty()) {
            return Collections.unmodifiableList(new ArrayList<Path>());
        }

        final List<String> pathStrings = splitPathStrings(property, multi);
        final ArrayList<Path> paths = new ArrayList<>();
        for (final String pathString : pathStrings) {
            if (pathString.isEmpty()) {
                continue;
            }

            final Path path;
            try {
                path = Paths.get(pathString);
            } catch (final InvalidPathException ex) {
                logger.error("Embulk system property \"" + propertyName + "\" in command-line is invalid: \"" + pathString + "\"", ex);
                throw ex;
            }

            final Path absolute;
            if (path.isAbsolute()) {
                absolute = path;
            } else {
                absolute = path.toAbsolutePath();
            }

            final Path normalized = absolute.normalize();
            if (!normalized.equals(path)) {
                logger.warn("Embulk system property \"" + propertyName + "\" in command-line is not normalized: "
                             + "\"" + pathString + "\", " + "then resolved to: \"" + normalized.toString() + "\"");
            }

            // Symbolic links are intentionally NOT resolved with Path#toRealPath.
            paths.add(normalized);
        }

        return Collections.unmodifiableList(paths);
    }
Returns normalized paths in a specified property from the command line.

<p>Note that a path in the command line should be an absolute path, or a relative path from the working directory.
embulk-core/src/main/java/org/embulk/cli/EmbulkSystemPropertiesBuilder.java