src/Database/Database.php
protected function public__quoteIdentifier($identifier)
    {
        $parts = \explode('.', $identifier);
        $parts = \array_map([$this, 'public__quoteIdentifierPart'], $parts);
        return \join('.', $parts);
    }
protected function public__quoteIdentifier($identifier)
    {
        $parts = \explode('.', $identifier);
        $parts = \array_map([$this, 'public__quoteIdentifierPart'], $parts);
        return \join('.', $parts);
    }
Quote a string that is used as an identifier
(table names, column names etc). This method can
also deal with dot-separated identifiers eg table.column

@param string $identifier
@return string