public static InstanceStatus toEnum(String str) {
            requireNonNull(str, "str");
            try {
                return valueOf(str);
            } catch (IllegalArgumentException e) {
                logger.warn("unknown enum value: {} (expected: {}), {} is set by default. ",
                            str, values(), UNKNOWN);
            }
            return UNKNOWN;
        }
Returns the {@link Enum} value corresponding to the specified {@code str}.
{@link #UNKNOWN} is returned if none of {@link Enum}s are matched.
eureka/src/main/java/com/linecorp/armeria/common/eureka/InstanceInfo.java