PhpCsFixer\Fixer\Basic\Psr0Fixer::fix PHP Method

    public function fix(\SplFileInfo $file, Tokens $tokens)
    {
        $namespace = false;
        $namespaceIndex = 0;
        $namespaceEndIndex = 0;
        $classyName = null;
        $classyIndex = 0;
        foreach ($tokens as $index => $token) {
            if ($token->isGivenKind(T_NAMESPACE)) {
                if (false !== $namespace) {
                    return;
                }
                $namespaceIndex = $tokens->getNextMeaningfulToken($index);
                $namespaceEndIndex = $tokens->getNextTokenOfKind($index, array(';'));
                $namespace = trim($tokens->generatePartialCode($namespaceIndex, $namespaceEndIndex - 1));
            } elseif ($token->isClassy()) {
                if (null !== $classyName) {
                    return;
                }
                $classyIndex = $tokens->getNextMeaningfulToken($index);
                $classyName = $tokens[$classyIndex]->getContent();
            }
        }
        if (null === $classyName) {
            return;
        }
        if (false !== $namespace) {
            $normNamespace = str_replace('\\', '/', $namespace);
            $path = str_replace('\\', '/', $file->getRealPath());
            $dir = dirname($path);
            if (isset($this->configuration['dir'])) {
                $dir = substr($dir, strlen(realpath($this->configuration['dir'])) + 1);
                if (false === $dir) {
                    $dir = '';
                }
                if (strlen($normNamespace) > strlen($dir)) {
                    if ('' !== $dir) {
                        $normNamespace = substr($normNamespace, -strlen($dir));
                    } else {
                        $normNamespace = '';
                    }
                }
            }
            $dir = substr($dir, -strlen($normNamespace));
            if (false === $dir) {
                $dir = '';
            }
            $filename = basename($path, '.php');
            if ($classyName !== $filename) {
                $tokens[$classyIndex]->setContent($filename);
            }
            if ($normNamespace !== $dir && strtolower($normNamespace) === strtolower($dir)) {
                for ($i = $namespaceIndex; $i <= $namespaceEndIndex; ++$i) {
                    $tokens[$i]->clear();
                }
                $namespace = substr($namespace, 0, -strlen($dir)) . str_replace('/', '\\', $dir);
                $newNamespace = Tokens::fromCode('<?php namespace ' . $namespace . ';');
                $newNamespace[0]->clear();
                $newNamespace[1]->clear();
                $newNamespace[2]->clear();
                $newNamespace->clearEmptyTokens();
                $tokens->insertAt($namespaceIndex, $newNamespace);
            }
        } else {
            $normClass = str_replace('_', '/', $classyName);
            $path = str_replace('\\', '/', $file->getRealPath());
            $filename = substr($path, -strlen($normClass) - 4, -4);
            if ($normClass !== $filename && strtolower($normClass) === strtolower($filename)) {
                $tokens[$classyIndex]->setContent(str_replace('/', '_', $filename));
            }
        }
    }