$overrides = array( 'test_form' => false, 'test_type' => false );
$_FILES['import']['name'] .= '.txt';
$file = wp_handle_upload( $_FILES['import'], $overrides );
$overrides = array( 'test_form' => false, 'test_type' => false );
$_FILES['import']['name'] .= '.txt';
$file = wp_handle_upload( $_FILES['import'], $overrides );