public function column($column, $type = 'string', $length = 255)
    {
        $this->builder->setDiscriminatorColumn($column, $type, $length);

        return $this;
    }
public function column($column, $type = 'string', $length = 255)
    {
        $this->builder->setDiscriminatorColumn($column, $type, $length);

        return $this;
    }
public function column ( $ column , $ type = 'string' , $ length = 255 ) { $ this -> builder -> setDiscriminatorColumn ( $ column , $ type , $ length ) ; return $ this ; }
Add the discriminator column.

@param string $column
@param string $type
@param int    $length

@return Inheritance
Add the discriminator column .