Added a method that allows to check if there are pending transmits with a given ID

Author: kjetilkjeka

src/can.rs

@@ -164,6 +164,9 @@ pub trait Transmitter: Interface {
     /// and return it. This is to avoid the priority inversion problem.
     fn transmit(&mut self, frame: &Self::Frame) -> nb::Result<Option<Self::Frame>, Self::Error>;
 
+    /// Returns true if there exists a pending transmit matching this filter.
+    fn pending_transmit(&self, filter: &Self::Filter) -> bool;
+
     /// Returns true if a call to `transmit(frame)` (and if the interface supports Can-FD)
     /// `transmit_fd(fd_frame)` would return a `Frame` or `WouldBlock`.
     fn transmit_buffer_full(&self) -> bool;