--- /dev/null
+--TEST--
+Test keys()
+--SKIPIF--
+<?php if (!extension_loaded("pimple")) print "skip"; ?>
+--FILE--
+<?php
+
+$p = new Pimple\Container();
+
+var_dump($p->keys());
+
+$p['foo'] = 'bar';
+$p[] = 'foo';
+
+var_dump($p->keys());
+
+unset($p['foo']);
+
+var_dump($p->keys());
+?>
+--EXPECTF--
+array(0) {
+}
+array(2) {
+ [0]=>
+ string(3) "foo"
+ [1]=>
+ int(0)
+}
+array(1) {
+ [0]=>
+ int(0)
+}
\ No newline at end of file