WP_Textdomain_Registry::get_path_from_lang_dir( string $domain, string $locale )

	private function get_path_from_lang_dir( $domain, $locale ) {
		$locations = $this->get_paths_for_domain( $domain );

		$found_location = false;

		foreach ( $locations as $location ) {
			if ( ! isset( $this->cached_mo_files[ $location ] ) ) {
				$this->set_cached_mo_files( $location );
			}

			$path = "$location/$domain-$locale.mo";

			foreach ( $this->cached_mo_files[ $location ] as $mo_path ) {
				if (
					! in_array( $domain, $this->domains_with_translations, true ) &&
					str_starts_with( str_replace( "$location/", '', $mo_path ), "$domain-" )
				) {
					$this->domains_with_translations[] = $domain;
				}

				if ( $mo_path === $path ) {
					$found_location = rtrim( $location, '/' ) . '/';
				}
			}
		}

		if ( $found_location ) {
			$this->set( $domain, $locale, $found_location );

			return $found_location;
		}

		// If no path is found for the given locale and a custom path has been set
		// using load_plugin_textdomain/load_theme_textdomain, use that one.
		if ( 'en_US' !== $locale && isset( $this->custom_paths[ $domain ] ) ) {
			$fallback_location = rtrim( $this->custom_paths[ $domain ], '/' ) . '/';
			$this->set( $domain, $locale, $fallback_location );
			return $fallback_location;
		}

		$this->set( $domain, $locale, false );

		return false;
	}