### Question:
RequestsUtilities { public static String toBboxValue(final Envelope envelope) { final StringBuilder builder = new StringBuilder(); final int dimEnv = envelope.getDimension(); for (int i=0; i<dimEnv; i++) { builder.append(envelope.getMinimum(i)).append(','); } for (int j=0; j<dimEnv; j++) { if (j>0) { builder.append(','); } builder.append(envelope.getMaximum(j)); } return builder.toString(); } private  RequestsUtilities(); static String toBboxValue(final Envelope envelope); static boolean toBoolean(final String strTransparent); static Color toColor(String background); static String toCrsCode(final Envelope envelope); static double toDouble(String value); static Envelope toEnvelope(final String bbox, final CoordinateReferenceSystem crs); static Envelope toEnvelope(final String bbox, final CoordinateReferenceSystem crs,
                    final String strElevation, final String strTime); static String toFormat(String format); static int toInt(String value); static List<Double[]> toCategoriesRange(final String ranges);  }### Answer:
@Test public void toBboxValueListTest() throws Exception { double[] min = {20.0, 35.0}; double[] max = {110.0, 80.0}; Envelope envelope = new GeneralEnvelope(min, max); String result = RequestsUtilities.toBboxValue(envelope); String expResult = "20.0,35.0,110.0,80.0"; assertEquals(expResult, result); }