static String simpleXMLEscape(String str) {
        // We could even use the 'more flexible' CDATA section but for now do the following:
        // The 'and' could be important sometimes but remove others
        return XML_ESCAPE_PATTERN.matcher(str.replace("&", "&amp;")).replaceAll("_");
    }
@Test
    public void testXMLEscape_issue572() {
        assertEquals("_", GpxConversions.simpleXMLEscape("<"));
        assertEquals("_blup_", GpxConversions.simpleXMLEscape("<blup>"));
        assertEquals("a&amp;b", GpxConversions.simpleXMLEscape("a&b"));
    }