gistfile1.txt

<?php

$fixture = new ArrayObject( array(
    'a',
    'b',
    'c',
) );

unset( $fixture[1] );

$fixture = new ArrayObject(
    array_values($fixture)
);

var_dump( $fixture );

# Warning: array_values(): The argument should be an array in /tmp/test.php on line 12
# 
# Fatal error: Uncaught exception 'InvalidArgumentException' with message 'Passed variable is not an array or object, using empty array instead' in /tmp/test.php:13
# Stack trace:
# #0 /tmp/test.php(13): ArrayObject->__construct(NULL)
# #1 {main}
#   thrown in /tmp/test.php on line 13
# 

?>