src/AbstractLinesBeforeNamespaceFixer.php
protected function fixLinesBeforeNamespace(Tokens $tokens, $index, $expectedMin, $expectedMax)
    {
        // Let's determine the total numbers of new lines before the namespace
        // and the opening token
        $precedingNewlines = 0;
        $newlineInOpening = false;
        $openingToken = null;
        for ($i = 1; $i <= 2; ++$i) {
            if (isset($tokens[$index - $i])) {
                $token = $tokens[$index - $i];
                if ($token->isGivenKind(T_OPEN_TAG)) {
                    $openingToken = $token;
                    $openingTokenIndex = $index - $i;
                    $newlineInOpening = false !== strpos($token->getContent(), "\n");
                    if ($newlineInOpening) {
                        ++$precedingNewlines;
                    }

                    break;
                }
                if (false === $token->isGivenKind(T_WHITESPACE)) {
                    break;
                }
                $precedingNewlines += substr_count($token->getContent(), "\n");
            }
        }

        if ($precedingNewlines >= $expectedMin && $precedingNewlines <= $expectedMax) {
            return;
        }

        $previousIndex = $index - 1;
        $previous = $tokens[$previousIndex];

        if (0 === $expectedMax) {
            // Remove all the previous new lines
            if ($previous->isWhitespace()) {
                $tokens->clearAt($previousIndex);
            }
            // Remove new lines in opening token
            if ($newlineInOpening) {
                $tokens[$openingTokenIndex] = new Token([T_OPEN_TAG, rtrim($openingToken->getContent()).' ']);
            }

            return;
        }

        $lineEnding = $this->whitespacesConfig->getLineEnding();
        $newlinesForWhitespaceToken = $expectedMax;
        if (null !== $openingToken) {
            // Use the configured line ending for the PHP opening tag
            $content = rtrim($openingToken->getContent());
            $newContent = $content.$lineEnding;
            $tokens[$openingTokenIndex] = new Token([T_OPEN_TAG, $newContent]);
            --$newlinesForWhitespaceToken;
        }
        if (0 === $newlinesForWhitespaceToken) {
            // We have all the needed new lines in the opening tag
            if ($previous->isWhitespace()) {
                // Let's remove the previous token containing extra new lines
                $tokens->clearAt($previousIndex);
            }

            return;
        }
        if ($previous->isWhitespace()) {
            // Fix the previous whitespace token
            $tokens[$previousIndex] = new Token([T_WHITESPACE, str_repeat($lineEnding, $newlinesForWhitespaceToken).substr($previous->getContent(), strrpos($previous->getContent(), "\n") + 1)]);
        } else {
            // Add a new whitespace token
            $tokens->insertAt($index, new Token([T_WHITESPACE, str_repeat($lineEnding, $newlinesForWhitespaceToken)]));
        }
    }
protected function fixLinesBeforeNamespace(Tokens $tokens, $index, $expectedMin, $expectedMax)
    {
        // Let's determine the total numbers of new lines before the namespace
        // and the opening token
        $precedingNewlines = 0;
        $newlineInOpening = false;
        $openingToken = null;
        for ($i = 1; $i <= 2; ++$i) {
            if (isset($tokens[$index - $i])) {
                $token = $tokens[$index - $i];
                if ($token->isGivenKind(T_OPEN_TAG)) {
                    $openingToken = $token;
                    $openingTokenIndex = $index - $i;
                    $newlineInOpening = false !== strpos($token->getContent(), "\n");
                    if ($newlineInOpening) {
                        ++$precedingNewlines;
                    }

                    break;
                }
                if (false === $token->isGivenKind(T_WHITESPACE)) {
                    break;
                }
                $precedingNewlines += substr_count($token->getContent(), "\n");
            }
        }

        if ($precedingNewlines >= $expectedMin && $precedingNewlines <= $expectedMax) {
            return;
        }

        $previousIndex = $index - 1;
        $previous = $tokens[$previousIndex];

        if (0 === $expectedMax) {
            // Remove all the previous new lines
            if ($previous->isWhitespace()) {
                $tokens->clearAt($previousIndex);
            }
            // Remove new lines in opening token
            if ($newlineInOpening) {
                $tokens[$openingTokenIndex] = new Token([T_OPEN_TAG, rtrim($openingToken->getContent()).' ']);
            }

            return;
        }

        $lineEnding = $this->whitespacesConfig->getLineEnding();
        $newlinesForWhitespaceToken = $expectedMax;
        if (null !== $openingToken) {
            // Use the configured line ending for the PHP opening tag
            $content = rtrim($openingToken->getContent());
            $newContent = $content.$lineEnding;
            $tokens[$openingTokenIndex] = new Token([T_OPEN_TAG, $newContent]);
            --$newlinesForWhitespaceToken;
        }
        if (0 === $newlinesForWhitespaceToken) {
            // We have all the needed new lines in the opening tag
            if ($previous->isWhitespace()) {
                // Let's remove the previous token containing extra new lines
                $tokens->clearAt($previousIndex);
            }

            return;
        }
        if ($previous->isWhitespace()) {
            // Fix the previous whitespace token
            $tokens[$previousIndex] = new Token([T_WHITESPACE, str_repeat($lineEnding, $newlinesForWhitespaceToken).substr($previous->getContent(), strrpos($previous->getContent(), "\n") + 1)]);
        } else {
            // Add a new whitespace token
            $tokens->insertAt($index, new Token([T_WHITESPACE, str_repeat($lineEnding, $newlinesForWhitespaceToken)]));
        }
    }
Make sure # of line breaks prefixing namespace is within given range.

@param Tokens $tokens
@param int    $index
@param int    $expectedMin min. # of line breaks
@param int    $expectedMax max. # of line breaks