[commands] Add Subsystem.idle() (#7815)

wpilibNewCommands/src/main/native/cpp/frc2/command/Subsystem.cpp

@@ -46,6 +46,10 @@ void Subsystem::Register() {
   return CommandScheduler::GetInstance().RegisterSubsystem(this);
 }
 
+CommandPtr Subsystem::Idle() {
+  return cmd::Idle({this});
+}
+
 CommandPtr Subsystem::RunOnce(std::function<void()> action) {
   return cmd::RunOnce(std::move(action), {this});
 }

wpilibNewCommands/src/main/native/include/frc2/command/Subsystem.h

@@ -121,6 +121,15 @@ class Subsystem {
    */
   void Register();
 
+  /**
+   * Constructs a command that does nothing until interrupted. Requires this
+   * subsystem.
+   *
+   * @return the command
+   */
+  [[nodiscard]]
+  CommandPtr Idle();
+
   /**
    * Constructs a command that runs an action once and finishes. Requires this
    * subsystem.