PHP: Simple repository classes

Repository.php

<?php

// Todo
// - Add arrary-like iterating capabilities

class Repository
{
    protected $attributes = array();

    public function __construct(array $attributes = array())
    {
        $this->attributes = $attributes;
    }

    public function set($item, $value)
    {
        $this->attributes[$item] = $value;
    }

    public function place($path, $value)
    {
        array_set($this->attributes, $path, $value);
    }

    public function merge(array $items)
    {
        $this->attributes = array_merge($this->attributes, $items);
    }

    public function append($item, $data)
    {
        if ($this->missing($item))
        {
            $this->set($item, $data);
            return;
        }

        if (is_array($this->attributes[$item]))
        {
            $this->merge(array($item => (array) $data));
            return;
        }

        $this->attributes[$item] .= $data;
    }

    public function get($item, $default = null)
    {
        return (isset($this->attributes[$item])) ? $this->attributes[$item] : $default;
    }

    public function find($path, $default = null)
    {
        return array_get($this->attributes, $path, $default);
    }

    public function all()
    {
        return $this->attributes;
    }

    public function exists($item)
    {
        return isset($this->attributes[$item]);
    }

    public function has($item)
    {
        return $this->exists($item);
    }

    public function missing($item)
    {
        return !$this->exists($item);
    }

    public function isEmpty($item)
    {
        return empty($this->attributes[$item]);
    }

    public function notEmpty($item)
    {
        return !$this->isEmpty($item);
    }

    public function remove($item)
    {
        unset($this->attributes[$item]);
    }

    public function reset($item, $default = null)
    {
        $this->attributes[$item] = $default;
    }

    public function __get($attribute)
    {
        return $this->get($attribute);
    }

    public function __set($attribute, $value)
    {
        $this->set($attribute, $value);
    }
}

StaticRepository

<?php

class StaticRepository
{
    protected static $repository;

    public static function setRepository(Repository $repo)
    {
        static::$repository = $repo;
    }

    public static function getRepository()
    {
        return static::$repository;
    }

    public static function __callStatic($method, $args)
    {
        if (method_exists(static::$repository, $method))
        {
            return call_user_func_array(array(static::$repository, $method), $args);
        }

        throw new BadMethodCallException("{$method} method doesn't exists in " . get_called_class() . ' or its repository');
    }

    public function __get($attribute)
    {
        return static::$repository->{$attribute};
    }

    public function __set($attribute, $value)
    {
        static::$repository->{$attribute} = $value;
    }
}