public function getColor(string $identifier): string
    {
        if (!isset($this->cache[$identifier])) {
            $this->cache[$identifier] = $this->rotateColor();
        }
        
        return $this->cache[$identifier];
    }
public function getColor(string $identifier): string
    {
        if (!isset($this->cache[$identifier])) {
            $this->cache[$identifier] = $this->rotateColor();
        }
        
        return $this->cache[$identifier];
    }
public function getColor ( string $ identifier ) : string { if ( ! isset ( $ this -> cache [ $ identifier ] ) ) { $ this -> cache [ $ identifier ] = $ this -> rotateColor ( ) ; } return $ this -> cache [ $ identifier ] ; }
Get the color for an identifier.

@param string $identifier Identifier.

@return string
Get the color for an identifier .