original_string: public static function get_undeletable_block_types() {
          global $CFG;
          $undeletableblocks = false;
          if (isset($CFG->undeletableblocktypes)) {
              $undeletableblocks = $CFG->undeletableblocktypes;
          }
  
          if (empty($undeletableblocks)) {
              return array();
          } else if (is_string($undeletableblocks)) {
              return explode(',', $undeletableblocks);
          } else {
              return $undeletableblocks;
          }
      }
code: public static function get_undeletable_block_types() {
          global $CFG;
          $undeletableblocks = false;
          if (isset($CFG->undeletableblocktypes)) {
              $undeletableblocks = $CFG->undeletableblocktypes;
          }
  
          if (empty($undeletableblocks)) {
              return array();
          } else if (is_string($undeletableblocks)) {
              return explode(',', $undeletableblocks);
          } else {
              return $undeletableblocks;
          }
      }
code_tokens: public static function get_undeletable_block_types ( ) { global $ CFG ; $ undeletableblocks = false ; if ( isset ( $ CFG -> undeletableblocktypes ) ) { $ undeletableblocks = $ CFG -> undeletableblocktypes ; } if ( empty ( $ undeletableblocks ) ) { return array ( ) ; } else if ( is_string ( $ undeletableblocks ) ) { return explode ( ',' , $ undeletableblocks ) ; } else { return $ undeletableblocks ; } }
docstring: Get the list of "protected" blocks via admin block manager ui.
  
  @return array names of block types that cannot be added or deleted. E.g. array('navigation','settings').
docstring_tokens: Get the list of protected blocks via admin block manager ui .