jadler-core/src/main/java/net/jadler/matchers/ParameterRequestMatcher.java
@Override
    protected List<String> retrieveValue(final Request req) {
        return req.getParameters().getValues(this.paramName);
    }
@Override
    protected List<String> retrieveValue(final Request req) {
        return req.getParameters().getValues(this.paramName);
    }
Retrieves a parameter (defined in {@link #ParameterRequestMatcher(org.hamcrest.Matcher, java.lang.String)})
of the given request. The values are percent-encoded.
@param req request to retrieve the parameter from
@return the request parameter as a list of values or {@code null} if there is no such a parameter in the request