use collections::HashMap; use crate::{KeybindingKeystroke, Keystroke}; /// A trait for platform-specific keyboard layoutspub trait PlatformKeyboardLayout {    /// Get the keyboard layout ID, which should be unique to the layout    fn id(&self) -> &str;    /// Get the keyboard layout display name    fn name(&self) -> &str;} /// A trait for platform-specific keyboard mappingspub trait PlatformKeyboardMapper {    /// Map a key equivalent to its platform-specific representation    fn map_key_equivalent(        &self,        keystroke: Keystroke,        use_key_equivalents: bool,    ) -> KeybindingKeystroke;    /// Get the key equivalents for the current keyboard layout,    /// only used on macOS    fn get_key_equivalents(&self) -> Option<&HashMap<char, char>>;} /// A dummy implementation of the platform keyboard mapperpub struct DummyKeyboardMapper; impl PlatformKeyboardMapper for DummyKeyboardMapper {    fn map_key_equivalent(        &self,        keystroke: Keystroke,        _use_key_equivalents: bool,    ) -> KeybindingKeystroke {        KeybindingKeystroke::from_keystroke(keystroke)    }     fn get_key_equivalents(&self) -> Option<&HashMap<char, char>> {        None    }}