hace_json.php

$unit = $this->get_mapped_unit( $entity['data']['units'] );

		$values = array_map( function($v) use ($unit) {
			if (strcmp($v, ".") !== 0) {
				return $v * $unit['multiplier'];
			} else {
				return null;
			}
		}, wp_list_pluck( $data, 'value' ) );

		$data = array(
			'interval'          => strtotime( $data[1]->date ) - strtotime( $data[0]->date ),
			'data'              => json_encode($values, JSON_NUMERIC_CHECK), //$values,
			'units'             => $unit['unit'],
			'start'             => strtotime( $data[0]->date ),
			'end'               => strtotime( $to ),
			'name'              => $entity['name'],
			'metric'            => $metric['name'],
			'source'            => $entity['data']['source']['name'],
			'observation_start' => $entity['data']['observation_start']
		);