Method observer

datafusion/datasource/src/morsel/mocks.rs:432–434

Returns the shared event observer for this test harness.

(&self)

    /// Returns the shared event observer for this test harness.
    pub(crate) fn observer(&self) -> &MorselObserver {
        &self.observer
    }

    /// Specify the return planner for the specified file_path
    pub(crate) fn with_planner(mut self, planner: impl Into<MockPlanner>) -> Self {