public static MappingRuleMatcher createAllMatcher() {
    return new MatchAllMatcher();
  }
@Test
  public void testToStrings() {
    MappingRuleMatcher var = new MappingRuleMatchers.VariableMatcher("%a", "b");
    MappingRuleMatcher all = MappingRuleMatchers.createAllMatcher();
    MappingRuleMatcher and = new MappingRuleMatchers.AndMatcher(var, all, var);
    MappingRuleMatcher or = new MappingRuleMatchers.OrMatcher(var, all, var);

    assertEquals("VariableMatcher{variable='%a', value='b'}", var.toString());
    assertEquals("MatchAllMatcher", all.toString());
    assertEquals("AndMatcher{matchers=[" + var.toString() +
        ", " + all.toString() +
        ", " + var.toString() + "]}", and.toString());
    assertEquals("OrMatcher{matchers=[" + var.toString() +
        ", " + all.toString() +
        ", " + var.toString() + "]}", or.toString());
  }