Indicates whether block-specific criteria allow access to the block.
Blocks with access restrictions that should always be applied, regardless of user-configured settings, should implement this method with that access control logic.
bool FALSE to deny access to the block, or TRUE to allow access.
Overrides BlockPluginInterface::access
public function access() {
// By default, the block is visible unless user-configured rules indicate
// that it should be hidden.
return TRUE;
}