57     fn read(&self, offset: usize, data: &mut [u8]) -> Result<()>;  in read()
89     data: Vec<u8>,  field
108             data: vec![erased_val; total],  in new()
120         self.data.dump();  in dump()
127         fd.write_all(&self.data)?;  in write_file()
163         for x in &mut self.data[offset .. offset + len] {  in erase()
194         if offset + payload.len() > self.data.len() {  in write()
214         let sub = &mut self.data[offset .. offset + payload.len()];  in write()
220     fn read(&self, offset: usize, data: &mut [u8]) -> Result<()> {  in read()
221         if offset + data.len() > self.data.len() {  in read()
225         let sub = &self.data[offset .. offset + data.len()];  in read()
226         data.copy_from_slice(sub);  in read()
260         self.data.len()  in device_size()