A singleton application cache

local-cache.php

<?php

class LocalCache {
  
  use Singleton;
  
  protected store = [];
  
  public function get($key, default = null) {
    return isset($this->store[$key])) ? $this->store[$key] : $default;
  }
  
  public function set($key, $value) {
    $this->store[$key] = $value;
  }
  
}