import org.apache.maven.api.annotations.Nullable;

/**
 * Defines a simple logging interface for Maven CLI operations. These operations happen "early", when there may
 * be no logging set up even. Implementations may be "accumulating", in which case {@link #drain()}  method should
 * be used.
 * <p>
 * This interface provides methods for logging messages at different severity levels
 * and supports logging with or without associated exceptions.
 *

<img src="/img/tutorial/path-operation-configuration/image01.png">

### Tags with Enums { #tags-with-enums }

If you have a big application, you might end up accumulating **several tags**, and you would want to make sure you always use the **same tag** for related *path operations*.

In these cases, it could make sense to store the tags in an `Enum`.

        // Execute second time - params should be fresh
        Object result2 = scriptExecutor.execute("modifyEngine", "script2");
        assertEquals(2, result2); // Should still be 2, not accumulating
    }

    @Test
    public void test_shutdown_withListener() {
        // Add shutdown listener
        TestShutdownListener listener = new TestShutdownListener();

#
#       The "traditional" practice of packing multiple parameters into a
#       space-separated string is a well documented source of bugs and security
#       problems, so this is (mostly) avoided, by progressively accumulating
#       options in "$@", and eventually passing that to Java.
#
#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;

          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableListMultimap(keyFunction, valueFunction);
  }

  /**
   * Returns a {@code Collector} accumulating entries into an {@code ImmutableListMultimap}. Each
   * input element is mapped to a key and a stream of values, each of which are put into the

        }
    }

    /**
     * Deletes old documents that have the same URL but different document IDs
     * as the documents in the provided list. This prevents duplicate documents
     * from accumulating in the index.
     *
     * @param searchEngineClient the search engine client to use for deletion
     * @param docList the list of new documents to check against

          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableListMultimap(keyFunction, valueFunction);
  }

  /**
   * Returns a {@code Collector} accumulating entries into an {@code ImmutableListMultimap}. Each
   * input element is mapped to a key and a stream of values, each of which are put into the

          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSetMultimap(keyFunction, valueFunction);
  }

  /**
   * Returns a {@code Collector} accumulating entries into an {@code ImmutableSetMultimap}. Each
   * input element is mapped to a key and a stream of values, each of which are put into the

                context.logger);
        return new InvokerException.ExitException(2);
    }

    protected void printErrors(C context, boolean showStackTrace, List<Logger.Entry> entries, Logger logger) {
        // if accumulating logger passed, this is "early failure", swap logger for stdErr and use that to emit log
        if (logger instanceof AccumulatingLogger) {
            logger = new SystemLogger(context.invokerRequest.stdErr().orElse(null));

          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSetMultimap(keyFunction, valueFunction);
  }

  /**
   * Returns a {@code Collector} accumulating entries into an {@code ImmutableSetMultimap}. Each
   * input element is mapped to a key and a stream of values, each of which are put into the