public function push(string $key, array $data)
	{
		if ($this->has($key) && is_array($value = $this->get($key)))
			   {
			$this->set($key, array_merge($value, $data));
		}
	}
public function push(string $key, array $data)
	{
		if ($this->has($key) && is_array($value = $this->get($key)))
			   {
			$this->set($key, array_merge($value, $data));
		}
	}
public function push ( string $ key , array $ data ) { if ( $ this -> has ( $ key ) && is_array ( $ value = $ this -> get ( $ key ) ) ) { $ this -> set ( $ key , array_merge ( $ value , $ data ) ) ; } }
Push new value onto session value that is array.

@param string $key  Identifier of the session property we are interested in.
@param array  $data value to be pushed to existing session key.

@return void
Push new value onto session value that is array .