Gets and clears flash from the stack.
string $type:
array $default Default value if $type doee not exist.:
string
Overrides FlashBagInterface::get
public function get($type, array $default = array()) {
  if (!$this
    ->has($type)) {
    return $default;
  }
  $return = $this->flashes[$type];
  unset($this->flashes[$type]);
  return $return;
}