If prefix is not specified then some unspecified string will be used. If suffix is not specified then ".tmp" will be used. If directory is not specified then the default temporary-file directory will be used.
The prefix argument, if specified, must be at least three characters long. It is recommended that the prefix be a short, meaningful string such as "job" or "mail".
Note: if the new file is created in a directory that is shared with all users,
it may get permissions allowing everyone to read it, thus creating a risk of leaking
sensitive information stored in this file.
To avoid this, it's recommended either to specify an explicit parent directory that is not shared widely,
or to use alternative ways of creating temporary files,
such as java.nio.file.Files.createTempFile
or the experimental
createTempFile function in the
IllegalArgumentException - if prefix is shorter than three symbols.
Return a file object corresponding to a newly-created file.