class JaxbCustomPropertiesAdapter extends XmlAdapter<JaxbCustomPropertiesAdapter.JaxbAdaptedMap, Map<String, String>> {

    @Override
    public Map<String, String> unmarshal(JaxbAdaptedMap jaxbAdaptedMap) {
        if (jaxbAdaptedMap == null) {
            return null;
        }
        return jaxbAdaptedMap.entries.stream()
                .collect(Collectors.toMap(JaxbAdaptedMapEntry::getName, JaxbAdaptedMapEntry::getValue));
    }

    @Override
    public JaxbAdaptedMap marshal(Map<String, String> originalMap) {<FILL_FUNCTION_BODY>}

    // Required to generate the XSD type in the same namespace.
    @XmlType(namespace = SolverConfig.XML_NAMESPACE)
    static class JaxbAdaptedMap {

        @XmlElement(name = "property", namespace = SolverConfig.XML_NAMESPACE)
        private List<JaxbAdaptedMapEntry> entries;

        private JaxbAdaptedMap() {
            // Required by JAXB
        }

        public JaxbAdaptedMap(List<JaxbAdaptedMapEntry> entries) {
            this.entries = entries;
        }
    }

    // Required to generate the XSD type in the same namespace.
    @XmlType(namespace = SolverConfig.XML_NAMESPACE)
    static class JaxbAdaptedMapEntry {

        @XmlAttribute
        private String name;

        @XmlAttribute
        private String value;

        public JaxbAdaptedMapEntry() {
        }

        public JaxbAdaptedMapEntry(String name, String value) {
            this.name = name;
            this.value = value;
        }

        public String getName() {
            return name;
        }

        public String getValue() {
            return value;
        }
    }
}

        if (originalMap == null) {
            return null;
        }
        List<JaxbAdaptedMapEntry> entries = originalMap.entrySet().stream()
                .map(entry -> new JaxbCustomPropertiesAdapter.JaxbAdaptedMapEntry(entry.getKey(), entry.getValue()))
                .collect(Collectors.toList());
        return new JaxbAdaptedMap(entries);
    
<no_super_class>