This test checks IDs on block-level FOs.

TODO: Test table-and-caption and table-caption once implemented.

Notes: The following FOs cannot be tested this way: table-body, table-header, table-footer, table-row, multi-switch, multi-case, multi-toggle, multi-properties, multi-property-set, page-sequence.

block1 here is text in the list item body header footer body-content block-container-content