Function assert_dynamic_neighbor_state 

pub fn assert_dynamic_neighbor_state<I, D, BC, CC>(
    core_ctx: &mut CC,
    device_id: CC::DeviceId,
    neighbor: SpecifiedAddr<I::Addr>,
    expected_state: DynamicNeighborState<D, BC>,
)
where
    I: Ip,
    D: LinkDevice + PartialEq,
    BC: NudBindingsContext<I, D, CC::DeviceId, TxMetadata: PartialEq>,
    CC: NudContext<I, D, BC>,

Asserts that the device_id’s neighbor is at expected_state.