### Question:
AtLeastOneFieldPresenceConstraint implements Constraint { @Override public String describe() { return description; } AtLeastOneFieldPresenceConstraint(String... fieldNames); @Override boolean evaluate(Schema schema, JsonNode node); @Override String describe();  }### Answer:
@Test public void describesItsBehaviour() { AtLeastOneFieldPresenceConstraint constraint = new AtLeastOneFieldPresenceConstraint("http", "https"); assertThat(constraint.describe(), is("At least one of ('http', 'https') must be present.")); }