How to override overloads for standard library? #101

@NotNull private static final Overload OVERLOAD_MATCHES = Overload.binary(Overloads.MatchesString, (lhs, rhs) -> {
  System.out.println("---override matches---");
  String inst = (String) lhs.value();
  String target = (String) rhs.value();
  boolean result = target.matches(inst);
  return result ? BoolT.True : BoolT.False;
});

@Test public void testMatchs() {
  boolean result1 = XrayCEL.eval("'1234'.matches(r'\\d+')");
  System.out.println(result1); // output: true

  boolean result2 = XrayCEL.eval("r'\\d+'.matches('1234')");
  System.out.println(result2); // output: false
}