}
            if (converter == null) {
                return value;
            }
        }
        try {
            if (value.getClass() == String.class) {
                return converter.getAsObject((String) value);
            }
            return converter.getAsString(value);
        } catch (final Throwable cause) {
            throw new ConverterRuntimeException(destPropertyName, value, cause);
        }

         *
         * @param value The ISO 8601 formatted date string.
         * @return The Timestamp object, or null if the string is empty.
         */
        @Override
        public Object getAsObject(final String value) {
            if (StringUtil.isEmpty(value)) {
                return null;
            }
            return new Timestamp(DEFAULT_DATE_PRINTER.parseMillis(value));
        }

        /**

            assertSame(copySubj, copy.getSubject(), "Clone should retain its cached Subject");
        } else {
            // If JAAS is not configured and getSubject() returns null, verify cloning still works
            assertNull(first, "First call to getSubject() returned null - JAAS not configured");

            // Clone should also return null for getSubject() calls
            Subject copySubj = copy.getSubject();

    /**
     * {@inheritDoc}
     *
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        return "Kerb5Authenticator[subject=" + (this.getSubject() != null ? this.getSubject().getPrincipals() : null) + ",user=" + this.user
                + ",realm=" + this.realm + "]";
    }

    }

    @Nested
    @DisplayName("getSubject edge cases")
    class SubjectTests {
        @Test
        @DisplayName("returns provided subject")
        void subject_non_null() {
            Subject s = new Subject();
            TestCredentials creds = new TestCredentials("X", false, false, s, false);
            assertSame(s, creds.getSubject());
        }

        @Test

    void setSubject_updatesSubject() {
        Kerb5Authenticator auth = new Kerb5Authenticator((Subject) null);
        assertNull(auth.getSubject());
        Subject subject = new Subject();
        auth.setSubject(subject);
        assertSame(subject, auth.getSubject());
    }

            putValue(data, "Sender", message.getSender());
            putValue(data, "Sent-Date", message.getSentDate());
            putValue(data, "Size", message.getSize());
            putValue(data, "Subject", message.getSubject());
            putValue(data, "Receipients", message.getAllRecipients());
            putValue(data, "To", message.getRecipients(Message.RecipientType.TO));

        if (t.isAssignableFrom(this.getClass())) {
            return (T) this;
        }
        return null;
    }

    @Override
    public Subject getSubject() {
        return null;
    }

    @Override
    public void refresh() throws CIFSException {
    }

    /**
     *
     * {@inheritDoc}
     *