delete dead code

namespace plotfx {

void dimension_add(

    DimensionMap* map,

    const std::string& key) {

  if (map->count(key)) {

    return;

  }

  DimensionConfig d;

  d.key = key;

  map->emplace(d.key, d);

}

std::vector<Color> series_to_colors(

    SeriesRef series,

    const DomainConfig& domain_config,

#pragma once

#include <string>

#include <unordered_map>

#include "source/domain.h"

#include "source/data_model.h"

#include "domain.h"

#include "data_model.h"

#include "graphics/measure.h"

namespace plotfx {

struct DimensionConfig {

  std::string key;

  DomainConfig domain;

};

using DimensionMap = std::unordered_map<std::string, DimensionConfig>;

template <typename T>

using DimensionMapFn = std::function<std::vector<T> (const Series&)>;

void dimension_add(

    DimensionMap* map,

    const std::string& key);

std::vector<Color> series_to_colors(

    SeriesRef series,

    const DomainConfig& domain_config,