code: protected function applyFix(\SplFileInfo $file, Tokens $tokens)
      {
          // These cause syntax errors.
          static $blacklistFuncNames = [
              [T_STRING, '__construct'],
              [T_STRING, '__destruct'],
              [T_STRING, '__clone'],
          ];
  
          for ($index = $tokens->count() - 1; 0 <= $index; --$index) {
              if (!$tokens[$index]->isGivenKind(T_FUNCTION)) {
                  continue;
              }
  
              $funcName = $tokens->getNextMeaningfulToken($index);
              if ($tokens[$funcName]->equalsAny($blacklistFuncNames, false)) {
                  continue;
              }
  
              $startIndex = $tokens->getNextTokenOfKind($index, ['{', ';']);
  
              if ($this->hasReturnTypeHint($tokens, $startIndex)) {
                  continue;
              }
  
              if ($tokens[$startIndex]->equals(';')) {
                  // No function body defined, fallback to PHPDoc.
                  if ($this->hasVoidReturnAnnotation($tokens, $index)) {
                      $this->fixFunctionDefinition($tokens, $startIndex);
                  }
  
                  continue;
              }
  
              if ($this->hasReturnAnnotation($tokens, $index)) {
                  continue;
              }
  
              $endIndex = $tokens->findBlockEnd(Tokens::BLOCK_TYPE_CURLY_BRACE, $startIndex);
  
              if ($this->hasVoidReturn($tokens, $startIndex, $endIndex)) {
                  $this->fixFunctionDefinition($tokens, $startIndex);
              }
          }
      }
docs: {@inheritdoc}