chore: fixes

src/main.rs

@@ -32,6 +32,7 @@ fn main() -> Result<()> {
         ));
     }
 
+    #[allow(unused_mut)]
     let mut monitor = udev_power_monitor::UdevPowerMonitor::new(&mut manager);
     monitor.start()
 }

src/power_state_change_manager.rs

@@ -8,6 +8,12 @@ pub struct PowerStateChangeManager {
     handlers: Vec<Rc<RefCell<Box<dyn PowerStateChangeHandler>>>>,
 }
 
+impl Default for PowerStateChangeManager {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl PowerStateChangeManager {
     pub fn new() -> Self {
         Self {

src/udev_power_monitor.rs

@@ -20,7 +20,7 @@ impl<'a> UdevPowerMonitor<'a> {
     }
 
     pub fn start(&mut self) -> Result<()> {
-        let mut monitor = MonitorBuilder::new()
+        let monitor = MonitorBuilder::new()
             .context("Failed to create udev monitor builder")?
             .match_subsystem_devtype("power_supply", "power_supply")
             .context("Failed to match subsystem and devtype")?