Function datafusion::physical_plan::expressions::case

pub fn case(
    expr: Option<Arc<dyn PhysicalExpr>>, 
    when_thens: &[(Arc<dyn PhysicalExpr>, Arc<dyn PhysicalExpr>)], 
    else_expr: Option<Arc<dyn PhysicalExpr>>
) -> Result<Arc<dyn PhysicalExpr>>

Create a CASE expression