example.php

<?php
protected static function _filters($model, $behavior)
    {
        Filters::apply($model, 'save', function ($params, $next) use ($behavior) {

            foreach ($behavior->config('fields') as $field) {
                $params['data'][$field] = static::_btcToSatoshi($behavior, $params['entity'], $field);
            }

            return $next($params);
        });
    }