-/// # fn read(&self, namespace: &str, sub_namespace: &str, key: &str) -> io::Result<Vec<u8>> { Ok(Vec::new()) }
-/// # fn write(&self, namespace: &str, sub_namespace: &str, key: &str, buf: &[u8]) -> io::Result<()> { Ok(()) }
-/// # fn remove(&self, namespace: &str, sub_namespace: &str, key: &str, lazy: bool) -> io::Result<()> { Ok(()) }
-/// # fn list(&self, namespace: &str, sub_namespace: &str) -> io::Result<Vec<String>> { Ok(Vec::new()) }
+/// # fn read(&self, primary_namespace: &str, secondary_namespace: &str, key: &str) -> io::Result<Vec<u8>> { Ok(Vec::new()) }
+/// # fn write(&self, primary_namespace: &str, secondary_namespace: &str, key: &str, buf: &[u8]) -> io::Result<()> { Ok(()) }
+/// # fn remove(&self, primary_namespace: &str, secondary_namespace: &str, key: &str, lazy: bool) -> io::Result<()> { Ok(()) }
+/// # fn list(&self, primary_namespace: &str, secondary_namespace: &str) -> io::Result<Vec<String>> { Ok(Vec::new()) }