code: public boolean getBooleanProperty(final String name, final boolean defaultValueIfAbsent,
              final boolean defaultValueIfPresent) {
          final String prop = getStringProperty(name);
          return prop == null ? defaultValueIfAbsent
                  : prop.isEmpty() ? defaultValueIfPresent : "true".equalsIgnoreCase(prop);
      }
docs: Gets the named property as a boolean value.
  
  @param name the name of the property to look up
  @param defaultValueIfAbsent the default value to use if the property is undefined
  @param defaultValueIfPresent the default value to use if the property is defined but not assigned
  @return the boolean value of the property or {@code defaultValue} if undefined.