code: public static boolean getBooleanProperty(@Nonnull LogManager manager, @Nullable String name, boolean defaultValue) {
          if (name == null) {
              return defaultValue;
          }
          String val = manager.getProperty(name);
          if (val == null) {
              return defaultValue;
          }
          val = val.toLowerCase();
          if (val.equals("true") || val.equals("1")) {
              return true;
          } else if (val.equals("false") || val.equals("0")) {
              return false;
          }
          return defaultValue;
      }
docs: Visible version of {@link java.util.logging.LogManager#getIntProperty(String, int)}.
  
  Method to get a boolean property.
  
  If the property is not defined or cannot be parsed we return the given default value.