preg_replace_callback(): Requires argument 2, 'Poem::replaceSpaces', to be a valid callback in ...
$text = preg_replace_callback( '/^( +)/m', array( 'Poem', 'replaceSpaces' ), $text );
preg_replace_callback(): Requires argument 2, 'Poem::replaceSpaces', to be a valid callback in ...
$text = preg_replace_callback( '/^( +)/m', array( 'Poem', 'replaceSpaces' ), $text );