/**
* @param block_base $block a block that appears on this page.
* @return boolean boolean whether the currently logged in user is allowed to delete this block.
*/
protected function user_can_delete_block($block)
{
return $this->page->user_can_edit_blocks() && $block->user_can_edit() && $block->user_can_addto($this->page) && !in_array($block->instance->blockname, self::get_undeletable_block_types());
}