original_string: public function getCustomerByExternalUid($customerExternalUid)
      {
          $requestData = new Get\RequestData();
          $requestData->setCustomerExternalUid($customerExternalUid);
  
          $customers = $this->getCustomers($requestData)->getResponse()->getCustomers();
  
          return isset($customers[0]) ? $customers[0] : null;
      }
code: public function getCustomerByExternalUid($customerExternalUid)
      {
          $requestData = new Get\RequestData();
          $requestData->setCustomerExternalUid($customerExternalUid);
  
          $customers = $this->getCustomers($requestData)->getResponse()->getCustomers();
  
          return isset($customers[0]) ? $customers[0] : null;
      }
code_tokens: public function getCustomerByExternalUid ( $ customerExternalUid ) { $ requestData = new Get \ RequestData ( ) ; $ requestData -> setCustomerExternalUid ( $ customerExternalUid ) ; $ customers = $ this -> getCustomers ( $ requestData ) -> getResponse ( ) -> getCustomers ( ) ; return isset ( $ customers [ 0 ] ) ? $ customers [ 0 ] : null ; }
docstring: Get once customer by the external ID.
  
  @param string $customerExternalUid The external customer ID.
  @return Customer|null
docstring_tokens: Get once customer by the external ID .