protected function set_variation_data( &$variation, $data ) {
		$parent = false;

		// Check if parent exist.
		if ( isset( $data['parent_id'] ) ) {
			$parent = wc_get_product( $data['parent_id'] );

			if ( $parent ) {
				$variation->set_parent_id( $parent->get_id() );
			}
		}

		// Stop if parent does not exists.
		if ( ! $parent ) {
			return new WP_Error( 'woocommerce_product_importer_missing_variation_parent_id', __( 'Variation cannot be imported: Missing parent ID or parent does not exist yet.', 'woocommerce' ), array( 'status' => 401 ) );
		}

		// Stop if parent is a product variation.
		if ( $parent->is_type( 'variation' ) ) {
			return new WP_Error( 'woocommerce_product_importer_parent_set_as_variation', __( 'Variation cannot be imported: Parent product cannot be a product variation', 'woocommerce' ), array( 'status' => 401 ) );
		}

		if ( isset( $data['raw_attributes'] ) ) {
			$attributes        = array();
			$parent_attributes = $this->get_variation_parent_attributes( $data['raw_attributes'], $parent );

			foreach ( $data['raw_attributes'] as $attribute ) {
				$attribute_id = 0;

				// Get ID if is a global attribute.
				if ( ! empty( $attribute['taxonomy'] ) ) {
					$attribute_id = $this->get_attribute_taxonomy_id( $attribute['name'] );
				}

				if ( $attribute_id ) {
					$attribute_name = wc_attribute_taxonomy_name_by_id( $attribute_id );
				} else {
					$attribute_name = sanitize_title( $attribute['name'] );
				}

				if ( ! isset( $parent_attributes[ $attribute_name ] ) || ! $parent_attributes[ $attribute_name ]->get_variation() ) {
					continue;
				}

				$attribute_key   = sanitize_title( $parent_attributes[ $attribute_name ]->get_name() );
				$attribute_value = isset( $attribute['value'] ) ? current( $attribute['value'] ) : '';

				if ( $parent_attributes[ $attribute_name ]->is_taxonomy() ) {
					// If dealing with a taxonomy, we need to get the slug from the name posted to the API.
					$term = get_term_by( 'name', $attribute_value, $attribute_name );

					if ( $term && ! is_wp_error( $term ) ) {
						$attribute_value = $term->slug;
					} else {
						$attribute_value = sanitize_title( $attribute_value );
					}
				}

				$attributes[ $attribute_key ] = $attribute_value;
			}

			$variation->set_attributes( $attributes );
		}
	}