The three methods in
o.n.s.masterfs.AutoMountProvider such as
createFileSystem take a String for the file path,
with this Javadoc:

"Corresponds to java.io.File.getAbstractPath. But
be aware, that this doesn't mean, that such file
must really exist. May also address virtual location."

Besides the fact that there is no such method as
getAbstractPath (getAbsolutePath I guess) this
does not explain why you don't simply use
java.io.File here, since you are referring to a
file path, and that is exactly what File is for. I
can imagine a typical provider would anyway just
wind up creating a File for the path in order to
check its children, etc.