code: public function getCustomerById(string $customerId): array
      {
          $cacheKey = sprintf('zoho_customer_%s', $customerId);
          $hit = $this->getFromCache($cacheKey);
  
          if (false === $hit) {
              $response = $this->sendRequest('GET', sprintf('customers/%s', $customerId));
              $result = $this->processResponse($response);
  
              $customer = $result['customer'];
  
              $this->saveToCache($cacheKey, $customer);
  
              return $customer;
          }
  
          return $hit;
      }
docs: @param string $customerId The customer's id
  
  @throws \Exception
  
  @return array