code: public boolean hasBooleanProperty( Property propertyId ) {
          Object value = getProperty(propertyId);
          return (value instanceof Boolean && ((Boolean)value).booleanValue());
      }
docs: Indicates if there is a non-null property value that equates to a <code>true</code> boolean value.
  
  @param propertyId the property identifier
  @return true if this node has value for the supplied property and that value is a boolean value of <code>true</code>