code: private String parseErrorCodeFromHeader(Map<String, String> httpHeaders) {
          String headerValue = httpHeaders.get(X_AMZN_ERROR_TYPE);
          if (headerValue != null) {
              int separator = headerValue.indexOf(':');
              if (separator != -1) {
                  headerValue = headerValue.substring(0, separator);
              }
          }
          return headerValue;
      }
docs: Attempt to parse the error code from the response headers. Returns null if information is not
  present in the header.