code/database/behavior/sluggable.php
public function getSlug()
    {
        if (!$this->_unique)
        {
            $column = $this->getIdentityColumn();
            $result = $this->{$column} . $this->_separator . $this->slug;
        }
        else $result = $this->slug;

        return $result;
    }
public function getSlug()
    {
        if (!$this->_unique)
        {
            $column = $this->getIdentityColumn();
            $result = $this->{$column} . $this->_separator . $this->slug;
        }
        else $result = $this->slug;

        return $result;
    }
public function getSlug ( ) { if ( ! $ this -> _unique ) { $ column = $ this -> getIdentityColumn ( ) ; $ result = $ this -> { $ column } . $ this -> _separator . $ this -> slug ; } else $ result = $ this -> slug ; return $ result ; }
Get the canonical slug

This function will always return a unique and canonical slug. If the slug is not unique it will prepend the
identity column value.

@link : https://en.wikipedia.org/wiki/Canonicalization

@return string
Get the canonical slug