See #50774. Built from https://develop.svn.wordpress.org/trunk@49249 git-svn-id: http://core.svn.wordpress.org/trunk@49011 1a063a9b-81f0-0310-95a4-ce76da25c4cd
instanceof
get_class()
$args
register_block_type()
WP_Block_Type
WP_Customize_Section::__construct()
WP_Customize_Manager::add_section()
WP_Textdomain_Registry