#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};
#[cfg(doc)]
use crate::prelude::Measurements;
use crate::prelude::{Epoch, EpochFlag};
#[derive(Clone, Debug, Default, PartialEq, PartialOrd, Eq, Ord, Hash)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub struct Key {
pub flag: EpochFlag,
pub epoch: Epoch,
}