A mock for Log while running tests for Android

Log.java

package android.util;

import java.util.Locale;

import static java.lang.System.out;

@SuppressWarnings("UnusedReturnValue")
public class Log {

    private static final int DEFAULT_RETURN_VALUE = 0;
    private static Locale DEFAULT_LOCALE = Locale.getDefault();

    public static int d(String tag, String message) {
        out.println(String.format(DEFAULT_LOCALE, "DEBUG: %s: %s", tag, message));

        return DEFAULT_RETURN_VALUE;
    }

    public static int i(String tag, String message) {
        out.println(String.format(DEFAULT_LOCALE, "INFO: %s: %s", tag, message));

        return DEFAULT_RETURN_VALUE;
    }

    public static int w(String tag, String message) {
        out.println(String.format(DEFAULT_LOCALE, "WARN: %s: %s", tag, message));

        return DEFAULT_RETURN_VALUE;
    }

}