cdm/src/main/java/ucar/nc2/dataset/DatasetUrl.java
static private ServiceType checkIfCdmr(String location) throws IOException {

    try (HTTPMethod method = HTTPFactory.Head(location + "?req=header")) {
      int statusCode = method.execute();
      if (statusCode >= 300) {
        if (statusCode == HttpStatus.SC_UNAUTHORIZED || statusCode == HttpStatus.SC_FORBIDDEN)
          throw new IOException("Unauthorized to open dataset " + location);
        else
          throw new IOException(location + " is not a valid URL, return status=" + statusCode);
      }

      Header h = method.getResponseHeader("Content-Description");
      if ((h != null) && (h.getValue() != null)) {
        String v = h.getValue();
        if (v.equalsIgnoreCase("ncstream"))
          return ServiceType.CdmRemote;
      }
    }
    return null;
  }
static private ServiceType checkIfCdmr(String location) throws IOException {

    try (HTTPMethod method = HTTPFactory.Head(location + "?req=header")) {
      int statusCode = method.execute();
      if (statusCode >= 300) {
        if (statusCode == HttpStatus.SC_UNAUTHORIZED || statusCode == HttpStatus.SC_FORBIDDEN)
          throw new IOException("Unauthorized to open dataset " + location);
        else
          throw new IOException(location + " is not a valid URL, return status=" + statusCode);
      }

      Header h = method.getResponseHeader("Content-Description");
      if ((h != null) && (h.getValue() != null)) {
        String v = h.getValue();
        if (v.equalsIgnoreCase("ncstream"))
          return ServiceType.CdmRemote;
      }
    }
    return null;
  }
cdmremote