use std::convert::{
    TryInto,
};
use std::fmt;
use std::fs;

use std::convert::{ TryInto };
use std::{fmt, fs};

use serde::{
    Serialize,
    Serializer,
};

use serde::{ Serialize, Serializer };

use keytree::{
    KeyTree,
    KeyTreeRef,
};
use keytree::serialize::{
    KeyTreeString,
    IntoKeyTree,
};
use time_series::{
    RegularTimeSeries,
};

use keytree::{ KeyTree, KeyTreeRef };
use keytree::serialize::{ KeyTreeString, IntoKeyTree };
use time_series::{ RegularTimeSeries };

use crate::{
    DataType,
    DateRange,
    MonthlyDate,
    SeriesId,
    SeriesMetaData,
    SeriesSpec,
};

use crate::{ DataType, DateRange, MonthlyDate, SeriesId, SeriesMetaData, SeriesSpec };

// Default height in pixels of a graphic.

/// Top level Javascript-facing data-structure, that is loaded into memory by the server, and acts
/// as an immutable datastore for time-series web-pages.

/// The values in `Json` that are served one per web-page.

/// A component of `Json` that is a single data series. Series are referenced by graphics through an
/// index, so that each series can be used multiple times, without being downloaded multiple times.

// === Time-series Specification ==================================================================

/// The top-level Fred-facing time-series specification. By convention, the file 'ts_spec.keytree'
/// can be deserialized into this type using the `KeyTree` library.

    // This function is responsible for converting `Spec` into `Json`. The iteration is simple, but
    // the building of `Json` is a little complex. This is the point where Fred-facing data-structures
    // meet Javascript-facing client data-structures, and hence the incongruence.

// === Transforms ==================================================================================