OpenFile
status_t result = OpenFile(state, mode, &data);
status_t result = OpenFile(fOpenState, newMode, &data);
status_t OpenFile(OpenState* state, int mode,
status_t error = OpenFile(*file);
virtual status_t OpenFile(BFile& file) = 0;
virtual status_t OpenFile(BFile& file);
virtual status_t OpenFile(BFile& file);
OpenFile(*ref);
void OpenFile(const entry_ref &ref);
OpenFile(ref);
void OpenFile(entry_ref* ref);