public function getEntityForElement( $element )
	{
		if ( isset( $element['contextRef'] ) )
		{
			return $this->contexts[ $element['contextRef'] ]['entity']['identifier']['value'];
		}

		if ( isset( $element['tuple_elements'] ) )
		{
			foreach ( $element['tuple_elements'] as $elementKey => $tuple_elements )
			{
				foreach ( $tuple_elements as $tupleIndex => $tuple_element )
				{
					$result = $this->getEntityForElement( $tuple_element );
					if ( $result ) return $result;
				}
			}
		}

		throw new Exception( "The element '{$element['taxonomy_element']['id']}' has no context ref but also has no tuple members (getEntityForElement)" );
	}