Test if the file is a folder or contains data.
Get input stream.
Get last modification time.
Lock the file. May do nothing if the underlying storage does not support
locking. This does not affe
Mark the file as being unimportant. If not called, the file is assumed to be
Get the MIME type of the file. If filesystem has no special support for MIME
types then can simply r
Test whether this file can be written to or not.
Get the size of the file.
Unlock the file.