createSync abstract method
Synchronously creates the file.
If recursive is false, the default, the file is created
only if all directories in its path already exist.
If recursive is true, all non-existing parent paths are created first.
If exclusive is true and to-be-created file already exists, this
operation completes the future with a FileSystemException.
If exclusive is false, existing files are left untouched by
createSync. Calling createSync on an existing file still might fail
if there are restrictive permissions on the file.
Throws a FileSystemException if the operation fails.
Implementation
void createSync({bool recursive = false, bool exclusive = false});