code: private function isNonNullableTypehintedNullableVariable(Tokens $tokens, $index)
      {
          $nextToken = $tokens[$tokens->getNextMeaningfulToken($index)];
  
          if (!$nextToken->equals([T_STRING, 'null'], false)) {
              return false;
          }
  
          $variableIndex = $tokens->getPrevMeaningfulToken($index);
  
          $searchTokens = [',', '(', [T_STRING], [CT::T_ARRAY_TYPEHINT], [T_CALLABLE]];
          $typehintKinds = [T_STRING, CT::T_ARRAY_TYPEHINT, T_CALLABLE];
  
          $prevIndex = $tokens->getPrevTokenOfKind($variableIndex, $searchTokens);
  
          if (!$tokens[$prevIndex]->isGivenKind($typehintKinds)) {
              return false;
          }
  
          return !$tokens[$tokens->getPrevMeaningfulToken($prevIndex)]->isGivenKind(CT::T_NULLABLE_TYPE);
      }
docs: @param Tokens $tokens
  @param int    $index  Index of "="
  
  @return bool