protected function set_attributes_query_args( &$query_args ) {
		if ( ! empty( $this->attributes['attribute'] ) || ! empty( $this->attributes['terms'] ) ) {
			$taxonomy = strstr( $this->attributes['attribute'], 'pa_' ) ? sanitize_title( $this->attributes['attribute'] ) : 'pa_' . sanitize_title( $this->attributes['attribute'] );
			$terms    = $this->attributes['terms'] ? array_map( 'sanitize_title', explode( ',', $this->attributes['terms'] ) ) : array();
			$field    = 'slug';

			if ( $terms && is_numeric( $terms[0] ) ) {
				$field = 'term_id';
				$terms = array_map( 'absint', $terms );
				// Check numeric slugs.
				foreach ( $terms as $term ) {
					$the_term = get_term_by( 'slug', $term, $taxonomy );
					if ( false !== $the_term ) {
						$terms[] = $the_term->term_id;
					}
				}
			}

			// If no terms were specified get all products that are in the attribute taxonomy.
			if ( ! $terms ) {
				$terms = get_terms(
					array(
						'taxonomy' => $taxonomy,
						'fields'   => 'ids',
					)
				);
				$field = 'term_id';
			}

			// We always need to search based on the slug as well, this is to accommodate numeric slugs.
			$query_args['tax_query'][] = array(
				'taxonomy' => $taxonomy,
				'terms'    => $terms,
				'field'    => $field,
				'operator' => $this->attributes['terms_operator'],
			);
		}
	}