protected String getRequestPayloadWithoutQueryParams(SignableRequest<?> request) {
        return newString(getBinaryRequestPayloadWithoutQueryParams(request));
    }
Returns the request's payload contents as a String, without processing
any query string params (i.e. no form encoding for query params).

@param request
           The request
@return the request's payload contents as a String, not including any
        form encoding of query string params.
aws-java-sdk-core/src/main/java/com/amazonaws/auth/AbstractAWSSigner.java