use ;
use crate::;
/// Trait for filling forward on an array, i.e., replacing nulls with the last non-null value.
///
/// If the array is non-nullable, it is returned as-is.
/// If the array is entirely nulls, the fill forward operation returns an array of the same length, filled with the default value of the array's type.
/// The DType of the returned array is the same as the input array; the Validity of the returned array is always either NonNullable or AllValid.