protected List<HeaderValue> parseHeaderValue(String headerValue) {
        return parseHeaderValue(headerValue, HEADER_VALUE_SEPARATOR, HEADER_QUALIFIER_SEPARATOR);
    }
@Test
    void headers_parseHeaderValue_multiValue() {
        AwsProxyHttpServletRequest request = new AwsProxyHttpServletRequest(contentTypeRequest, mockContext, null, config);
        // I'm also using this to double-check that I can get a header ignoring case
        List<AwsHttpServletRequest.HeaderValue> values = request.parseHeaderValue(request.getHeader("content-type"));

        assertEquals(2, values.size());
        assertEquals("application/xml", values.get(0).getValue());
        assertNull(values.get(0).getKey());

        assertEquals("charset", values.get(1).getKey());
        assertEquals("utf-8", values.get(1).getValue());
    }