* This interface provides methods for logging messages at different severity levels
 * and supports logging with or without associated exceptions.
 *
 * @since 4.0.0
 */
@Experimental
public interface Logger {

    /**
     * Represents the severity levels for log messages.
     */
    enum Level {
        DEBUG,
        INFO,
        WARN,
        ERROR
    }

${includes} = ?"${maven.user.conf}/maven.properties", \
              ?"${maven.project.conf}/maven.properties"

#
# Settings
#
# Define the default three levels for settings.
# The '-is' flag will override the 'maven.installation.settings' property.
# The '-ps' flag will override the 'maven.project.settings' property.
# The '-s' flag will override the 'maven.user.settings' property.

 * that exhibits the problem.
 *
 */
public interface Problem {

    /**
     * The different severity levels for a problem, in decreasing order.
     */
    enum Severity {
        FATAL, //
        ERROR, //
        WARNING //
    }

    /**

    // optimistically fill index position with elements from lower levels,
    // moving the hole down. In most cases this reduces the number of
    // comparisons with toTrickle, but in some cases we will need to bubble it
    // all the way up again.
    int vacated = heap.fillHoleAt(index);
    // Try to see if toTrickle can be bubbled up min levels.
    int bubbledTo = heap.bubbleUpAlternatingLevels(vacated, toTrickle);

    // optimistically fill index position with elements from lower levels,
    // moving the hole down. In most cases this reduces the number of
    // comparisons with toTrickle, but in some cases we will need to bubble it
    // all the way up again.
    int vacated = heap.fillHoleAt(index);
    // Try to see if toTrickle can be bubbled up min levels.
    int bubbledTo = heap.bubbleUpAlternatingLevels(vacated, toTrickle);

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

/**
 * Proto {@link Logger}. Uses provided {@link PrintStream}s or {@link System} ones as fallback.
 * Supports only two levels: ERROR and WARNING, that is emitted to STDERR and STDOUT.
 */
public class ProtoLogger implements Logger {

    private final PrintWriter out;
    private final PrintWriter err;

    public ProtoLogger() {

## Team

There's a team of people that help manage and maintain the project. 😎

They have different levels of permissions and [specific instructions](./management-tasks.md){.internal-link target=_blank}.

Some of the tasks they can perform include:

* Adding labels to PRs.
* Editing PR titles.

    void setLog(Log log);

    /**
     * Furnish access to the standard Maven logging mechanism which is managed in this base class.
     *
     * @return a log4j-like logger object which allows plugins to create messages at levels of <code>"debug"</code>,
     * <code>"info"</code>, <code>"warn"</code>, and <code>"error"</code>.
     * @deprecated Use SLF4J directly
     */
    @Deprecated
    Log getLog();

Using the below example document:
<img width="85%" src="https://bradley.codes/static/img/jstream-levels.gif" alt="jstream"/>

we can choose to extract and act only the objects within the top-level array:
```go
f, _ := os.Open("input.json")
decoder := jstream.NewDecoder(f, 1) // extract JSON values at a depth level of 1

 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services.SettingsBuilder} instead
 */
@Deprecated(since = "4.0.0")
public interface SettingsProblem {

    /**
     * The different severity levels for a problem, in decreasing order.
     */
    enum Severity {
        FATAL, //
        ERROR, //
        WARNING //
    }

    /**