code: public FulltextMatch addProperty(
                      final String property
                      )
      {
          if (property == null) {
              throw new IllegalArgumentException( "no property specified" );
          }
  
          _properties.add( property );
  
          return this;
      }
docs: Appends the specified property.
  
  @param   property
  the property to be appended.
  @throws  IllegalArgumentException
  if the specified property is null.