pub trait Operator {
// Required method
fn next(&mut self) -> Option<Row>;
// Provided methods
fn next_batch(&mut self, batch_size: usize) -> Option<Vec<Row>> { ... }
fn rows_examined(&self) -> usize { ... }
}pub trait Operator {
// Required method
fn next(&mut self) -> Option<Row>;
// Provided methods
fn next_batch(&mut self, batch_size: usize) -> Option<Vec<Row>> { ... }
fn rows_examined(&self) -> usize { ... }
}