$f.isReadOnly() :: $f instanceof org.openide.filesystems.FileObject
=>
!$f.canWrite()
;;

$f.getURL().toURI() :: $f instanceof org.openide.filesystems.FileObject
=>
$f.toURI()
;;

java.net.URI.create($f.getURL().toString()) :: $f instanceof org.openide.filesystems.FileObject
=>
$f.toURI()
;;

new java.net.URI($f.getURL().toString()) :: $f instanceof org.openide.filesystems.FileObject
=>
$f.toURI()
;;

java.net.URI.create($f.getURL().toExternalForm()) :: $f instanceof org.openide.filesystems.FileObject
=>
$f.toURI()
;;

new java.net.URI($f.getURL().toExternalForm()) :: $f instanceof org.openide.filesystems.FileObject
=>
$f.toURI()
;;

$f.getURL() :: $f instanceof org.openide.filesystems.FileObject
=>
$f.toURL()
;;