WP_REST_Themes_Controller::prepare_item_for_response

	public function prepare_item_for_response( $theme, $request ) {
		$data   = array();
		$fields = $this->get_fields_for_response( $request );

		if ( rest_is_field_included( 'stylesheet', $fields ) ) {
			$data['stylesheet'] = $theme->get_stylesheet();
		}

		if ( rest_is_field_included( 'template', $fields ) ) {
			/**
			 * Use the get_template() method, not the 'Template' header, for finding the template.
			 * The 'Template' header is only good for what was written in the style.css, while
			 * get_template() takes into account where WordPress actually located the theme and
			 * whether it is actually valid.
			 */
			$data['template'] = $theme->get_template();
		}

		$plain_field_mappings = array(
			'requires_php' => 'RequiresPHP',
			'requires_wp'  => 'RequiresWP',
			'textdomain'   => 'TextDomain',
			'version'      => 'Version',
		);

		foreach ( $plain_field_mappings as $field => $header ) {
			if ( rest_is_field_included( $field, $fields ) ) {
				$data[ $field ] = $theme->get( $header );
			}
		}

		if ( rest_is_field_included( 'screenshot', $fields ) ) {
			// Using $theme->get_screenshot() with no args to get absolute URL.
			$data['screenshot'] = $theme->get_screenshot() ? $theme->get_screenshot() : '';
		}

		$rich_field_mappings = array(
			'author'      => 'Author',
			'author_uri'  => 'AuthorURI',
			'description' => 'Description',
			'name'        => 'Name',
			'tags'        => 'Tags',
			'theme_uri'   => 'ThemeURI',
		);

		foreach ( $rich_field_mappings as $field => $header ) {
			if ( rest_is_field_included( "{$field}.raw", $fields ) ) {
				$data[ $field ]['raw'] = $theme->display( $header, false, true );
			}

			if ( rest_is_field_included( "{$field}.rendered", $fields ) ) {
				$data[ $field ]['rendered'] = $theme->display( $header );
			}
		}

		if ( rest_is_field_included( 'theme_supports', $fields ) ) {
			foreach ( get_registered_theme_features() as $feature => $config ) {
				if ( ! is_array( $config['show_in_rest'] ) ) {
					continue;
				}

				$name = $config['show_in_rest']['name'];