public function setTopic($value)
    {
        $this->assertValidString($value, false);
        if ($value === '') {
            throw new \InvalidArgumentException('The topic must not be empty.');
        }

        $this->topic = $value;
    }
public function setTopic($value)
    {
        $this->assertValidString($value, false);
        if ($value === '') {
            throw new \InvalidArgumentException('The topic must not be empty.');
        }

        $this->topic = $value;
    }
public function setTopic ( $ value ) { $ this -> assertValidString ( $ value , false ) ; if ( $ value === '' ) { throw new \ InvalidArgumentException ( 'The topic must not be empty.' ) ; } $ this -> topic = $ value ; }
Sets the topic.

@param string $value

@throws \InvalidArgumentException
Sets the topic .