async function() {
      if (!this.__mtime) {
        return this.read(); 
      }
      var poFile = this.getPoFilename();
      let stat = await qx.tool.compiler.files.Utils.safeStat(poFile);
      if (stat && this.__mtime == stat.mtime) {
        return undefined;
      }
      return this.read();
    }
async function() {
      if (!this.__mtime) {
        return this.read(); 
      }
      var poFile = this.getPoFilename();
      let stat = await qx.tool.compiler.files.Utils.safeStat(poFile);
      if (stat && this.__mtime == stat.mtime) {
        return undefined;
      }
      return this.read();
    }
async function ( ) { if ( ! this . __mtime ) { return this . read ( ) ; } var poFile = this . getPoFilename ( ) ; let stat = await qx . tool . compiler . files . Utils . safeStat ( poFile ) ; if ( stat && this . __mtime == stat . mtime ) { return undefined ; } return this . read ( ) ; }
Reads the .po file, but only if it has not been loaded or has changed

@returns {Promise}|
Reads the . po file but only if it has not been loaded or has changed