src/Tokenizer/Transformer/NullableTypeTransformer.php
public function process(Tokens $tokens, Token $token, $index)
    {
        if (!$token->equals('?')) {
            return;
        }

        $prevIndex = $tokens->getPrevMeaningfulToken($index);
        $prevToken = $tokens[$prevIndex];

        if ($prevToken->equalsAny(['(', ',', [CT::T_TYPE_COLON]])) {
            $tokens[$index] = new Token([CT::T_NULLABLE_TYPE, '?']);
        }
    }
public function process(Tokens $tokens, Token $token, $index)
    {
        if (!$token->equals('?')) {
            return;
        }

        $prevIndex = $tokens->getPrevMeaningfulToken($index);
        $prevToken = $tokens[$prevIndex];

        if ($prevToken->equalsAny(['(', ',', [CT::T_TYPE_COLON]])) {
            $tokens[$index] = new Token([CT::T_NULLABLE_TYPE, '?']);
        }
    }
{@inheritdoc}