Magento 2 - Include Static Blocks (template/cms/layout)

magento2-include-static-blocks.md

In .phtml tempalte file:

<?php echo $block->getLayout()->createBlock('Magento\Cms\Block\Block')->setBlockId('block_identifier')->toHtml();?>

In CMS content:

{{block class="Magento\\Cms\\Block\\Block" block_id="block_identifier"}}

In layout .xml file:

<referenceContainer name="content">
  <block class="Magento\Cms\Block\Block" name="block_identifier">
    <arguments>
      <argument name="block_id" xsi:type="string">block_identifier</argument>
    </arguments>
  </block>
</referenceContainer>

I have a problem with the xml method. The block is added to the layout, but its' _toHtml() is never called, so this block does not appear on the page.

EDIT:
My bad, didn't notice name="block_id" was crucial here and didn't need to be changed, as it is an id of the argument!