@Test
    void testHttpHostConnectExceptionFromCause() {
        final IOException cause = new IOException("something awful");
        final HttpHostConnectException ctx = ConnectExceptionSupport.createHttpHostConnectException(cause, null);
        Assertions.assertEquals("Connect to remote endpoint failed: something awful", ctx.getMessage());
    }
Unit tests for exceptions.
Trivial, but it looks better in the Clover reports.
httpclient5/src/test/java/org/apache/hc/client5/http/ConnectExceptionSupportTest.java