Method try_pushdown_projection

datafusion/datasource/src/test_util.rs:109–121

(
        &self,
        projection: &datafusion_physical_plan::projection::ProjectionExprs,
    )

    }

    fn try_pushdown_projection(
        &self,
        projection: &datafusion_physical_plan::projection::ProjectionExprs,
    ) -> Result<Option<Arc<dyn FileSource>>> {
        let mut source = self.clone();
        let new_projection = self.projection.source.try_merge(projection)?;
        let split_projection = crate::projection::SplitProjection::new(
            self.table_schema.file_schema(),
            &new_projection,
        );
        source.projection = split_projection;
        Ok(Some(Arc::new(source)))
    }

    fn projection(
        &self,