public function offsetSet($offset, $value): void
    {
        if ($this->contains($value)) {
            return;
        }

        parent::offsetSet($offset, $value);
    }
public function offsetSet($offset, $value): void
    {
        if ($this->contains($value)) {
            return;
        }

        parent::offsetSet($offset, $value);
    }
public function offsetSet ( $ offset , $ value ) : void { if ( $ this -> contains ( $ value ) ) { return ; } parent :: offsetSet ( $ offset , $ value ) ; }
Sets the given value to the given offset in this set, if it is not
already present.

@param mixed|null $offset The offset is ignored and is treated as `null`.
@param mixed $value The value to set at the given offset.

@throws InvalidArgumentException when the value does not match the
specified type for this set.
Sets the given value to the given offset in this set if it is not already present .