This service displays a file selection dialog with the specified title (if any) in which the user can browse the file system to select a file. The fileExtensions port specifies a comma separated list of the file extensions that the user can use to filter their view of the files. The fileExtLabels contains a comma separated list with the same number of elements. Each entry in fileExtLabels specifies the text by which the corresponding file extension will be displayed to the user. For example, if fileExtensions is 'bin,txt' then a sensible value for fileExtLabels is 'binary files, text files'. If no filtering of the files is to be made available then fileExtensions and fileExtLabels should be set to the empty string. The user always has the option to view all files. When the user clicks Open, the service outputs the path to the selected file to the selectedFile port. If the user clicks Cancel then an exception is generated.