src/Core/HttpClients/SyncRestHandler.php
private function setCommonHeadersForPHPSDK($AuthorizationHeader, $requestUri, $ContentType, $requestBody){
      $httpHeaders = array(
          'Authorization' => $AuthorizationHeader,
          'host'          => parse_url($requestUri, PHP_URL_HOST),
          'user-agent'    => CoreConstants::USERAGENT,
          'accept'        => $this->getAcceptContentType($ContentType),
          'connection'    => 'close',
          'content-type'  => $ContentType,
          'content-length'=> strlen($requestBody)
      );

      return $httpHeaders;
    }
private function setCommonHeadersForPHPSDK($AuthorizationHeader, $requestUri, $ContentType, $requestBody){
      $httpHeaders = array(
          'Authorization' => $AuthorizationHeader,
          'host'          => parse_url($requestUri, PHP_URL_HOST),
          'user-agent'    => CoreConstants::USERAGENT,
          'accept'        => $this->getAcceptContentType($ContentType),
          'connection'    => 'close',
          'content-type'  => $ContentType,
          'content-length'=> strlen($requestBody)
      );

      return $httpHeaders;
    }
Set the Common Headers for PHP SDK. It is used in all HTTP Request
@param  String $AuthorizationHeader    The authorizationHeader
@param  String $requestUri             The request URI
@param  String $ContentType            The content type
@param  String $requestBody            The request Body

@return array theStandard HTTP Header