Sets the HTTP methods (e.g. 'POST') this route is restricted to. So an empty array means that any method is allowed.
This method implements a fluent interface.
string|array $methods The method or an array of methods:
Route The current Route instance
public function setMethods($methods) {
  $this->methods = array_map('strtoupper', (array) $methods);
  // this is to keep BC and will be removed in a future version
  if ($this->methods) {
    $this->requirements['_method'] = implode('|', $this->methods);
  }
  else {
    unset($this->requirements['_method']);
  }
  $this->compiled = null;
  return $this;
}