code: protected function applyFix(\SplFileInfo $file, Tokens $tokens)
      {
          $replacements = [];
          $escapeSequences = [];
          foreach ($this->symbolsReplace as $character => list($replacement, $codepoint)) {
              $replacements[$character] = $replacement;
              $escapeSequences[$character] = '\u{'.$codepoint.'}';
          }
  
          foreach ($tokens as $index => $token) {
              $content = $token->getContent();
  
              if (
                  $this->configuration['use_escape_sequences_in_strings']
                  && $token->isGivenKind([T_CONSTANT_ENCAPSED_STRING, T_ENCAPSED_AND_WHITESPACE])
              ) {
                  if (!Preg::match('/'.implode('|', array_keys($escapeSequences)).'/', $content)) {
                      continue;
                  }
  
                  $previousToken = $tokens[$index - 1];
                  $stringTypeChanged = false;
  
                  if ($previousToken->isGivenKind(T_START_HEREDOC)) {
                      $previousTokenContent = $previousToken->getContent();
  
                      if (false !== strpos($previousTokenContent, '\'')) {
                          $tokens[$index - 1] = new Token([T_START_HEREDOC, str_replace('\'', '', $previousTokenContent)]);
                          $stringTypeChanged = true;
                      }
                  } elseif ("'" === $content[0]) {
                      $content = Preg::replace('/^\'(.*)\'$/', '"$1"', $content);
                      $stringTypeChanged = true;
                  }
  
                  if ($stringTypeChanged) {
                      $content = Preg::replace('/([\\\\$])/', '\\\\$1', $content);
                  }
  
                  $tokens[$index] = new Token([$token->getId(), strtr($content, $escapeSequences)]);
  
                  continue;
              }
  
              if ($token->isGivenKind(self::$tokens)) {
                  $tokens[$index] = new Token([$token->getId(), strtr($content, $replacements)]);
              }
          }
      }
docs: {@inheritdoc}