original_string: public function setAuthSubPrivateKey($key, $passphrase = null) {
          if ($key != null && !function_exists('openssl_pkey_get_private')) {
              require_once 'Zend/Gdata/App/InvalidArgumentException.php';
              throw new Zend_Gdata_App_InvalidArgumentException(
                      'You cannot enable secure AuthSub if the openssl module ' .
                      'is not enabled in your PHP installation.');
          }
          $this->_authSubPrivateKeyId = openssl_pkey_get_private(
                  $key, $passphrase);
          return $this;
      }
code: public function setAuthSubPrivateKey($key, $passphrase = null) {
          if ($key != null && !function_exists('openssl_pkey_get_private')) {
              require_once 'Zend/Gdata/App/InvalidArgumentException.php';
              throw new Zend_Gdata_App_InvalidArgumentException(
                      'You cannot enable secure AuthSub if the openssl module ' .
                      'is not enabled in your PHP installation.');
          }
          $this->_authSubPrivateKeyId = openssl_pkey_get_private(
                  $key, $passphrase);
          return $this;
      }
code_tokens: public function setAuthSubPrivateKey ( $ key , $ passphrase = null ) { if ( $ key != null && ! function_exists ( 'openssl_pkey_get_private' ) ) { require_once 'Zend/Gdata/App/InvalidArgumentException.php' ; throw new Zend_Gdata_App_InvalidArgumentException ( 'You cannot enable secure AuthSub if the openssl module ' . 'is not enabled in your PHP installation.' ) ; } $ this -> _authSubPrivateKeyId = openssl_pkey_get_private ( $ key , $ passphrase ) ; return $ this ; }
docstring: Sets the PEM formatted private key to be used for secure AuthSub auth.
  
  In order to call this method, openssl must be enabled in your PHP
  installation.  Otherwise, a Zend_Gdata_App_InvalidArgumentException
  will be thrown.
  
  @param string $key The private key
  @param string $passphrase The optional private key passphrase
  @throws Zend_Gdata_App_InvalidArgumentException
  @return Zend_Gdata_HttpClient Provides a fluent interface
docstring_tokens: Sets the PEM formatted private key to be used for secure AuthSub auth .