public function unshift($object): self
    {
        $this->internalDataListUpdate();
        array_unshift($this->internalDataListData, $object);
        return $this;
    }
public function unshift($object): self
    {
        $this->internalDataListUpdate();
        array_unshift($this->internalDataListData, $object);
        return $this;
    }
public function unshift ( $ object ) : self { $ this -> internalDataListUpdate ( ) ; array_unshift ( $ this -> internalDataListData , $ object ) ; return $ this ; }
Prepends an object to the beginning of the list.

@param object|array $object The data to be prepended.
@return self A reference to the list.
@throws \InvalidArgumentException
Prepends an object to the beginning of the list .