'Returns whether the block with the given block_key should
be hidden, given the current time.'

def _is_block_hidden(self, block_structure, block_key):

    hide_after_due = self._get_merged_hide_after_due(block_structure, block_key)
    self_paced = block_structure[block_structure.root_block_usage_key].self_paced
    if self_paced:
        hidden_date = block_structure[block_structure.root_block_usage_key].end
    else:
        hidden_date = self._get_merged_due_date(block_structure, block_key)
    return (not SequenceModule.verify_current_content_visibility(hidden_date, hide_after_due))
