String MAIL_SMTP_SERVER_MAIN_HOST_AND_PORT = "mail.smtp.server.main.host.and.port";

    /** The key of the configuration. e.g. [Test] */
    String MAIL_SUBJECT_TEST_PREFIX = "mail.subject.test.prefix";

    /** The key of the configuration. e.g. root@localhost */
    String MAIL_RETURN_PATH = "mail.return.path";

    /**
     * Get the value of property as {@link String}.

                is((Object) "1"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testConvertValue_propertyConverter_asObject() throws Exception {
        assertThat(new CopyOptions().converter(new NumberConverter("##0"), BeanNames.aaa()).convertValue("1", "aaa", null),
                is((Object) 1L));
    }

    /**

            defaultMap.put(FessConfig.MAIL_SEND_MOCK, "true");
            defaultMap.put(FessConfig.MAIL_SMTP_SERVER_MAIN_HOST_AND_PORT, "localhost:25");
            defaultMap.put(FessConfig.MAIL_SUBJECT_TEST_PREFIX, "[Test]");
            defaultMap.put(FessConfig.MAIL_RETURN_PATH, "root@localhost");
            return defaultMap;
        }
    }

import java.util.List;
import java.util.Set;

import javax.security.auth.Subject;
import javax.security.auth.kerberos.KerberosKey;
import javax.security.auth.kerberos.KeyTab;
import javax.security.auth.login.LoginContext;
import javax.security.auth.login.LoginException;


@SuppressWarnings ( "javadoc" )
public class KerberosCredentials {

    private Subject subject;


    public KerberosCredentials () throws LoginException {

            }

            @Override
            protected OptionalThing<SMailSubjectFilter> createSubjectFilter() {
                return OptionalThing.of((view, subject) -> subject);
            }

            @Override
            protected OptionalThing<SMailAsyncStrategy> createAsyncStrategy() {
                return OptionalThing.of((view, runnable) -> async(asyncManager, runnable));