src/Carbon/Language.php
public function getRegionName(): ?string
    {
        return $this->region ? (static::regions()[$this->region] ?? $this->region) : null;
    }
public function getRegionName(): ?string
    {
        return $this->region ? (static::regions()[$this->region] ?? $this->region) : null;
    }
public function getRegionName ( ) : ? string { return $ this -> region ? ( static :: regions ( ) [ $ this -> region ] ?? $ this -> region ) : null ; }
Returns the region name for the current language.

@return string|null
Returns the region name for the current language .