code: public static boolean isSentToCltvPaymentChannel(Script script) {
          List<ScriptChunk> chunks = script.chunks;
          if (chunks.size() != 10) return false;
          // Check that opcodes match the pre-determined format.
          if (!chunks.get(0).equalsOpCode(OP_IF)) return false;
          // chunk[1] = recipient pubkey
          if (!chunks.get(2).equalsOpCode(OP_CHECKSIGVERIFY)) return false;
          if (!chunks.get(3).equalsOpCode(OP_ELSE)) return false;
          // chunk[4] = locktime
          if (!chunks.get(5).equalsOpCode(OP_CHECKLOCKTIMEVERIFY)) return false;
          if (!chunks.get(6).equalsOpCode(OP_DROP)) return false;
          if (!chunks.get(7).equalsOpCode(OP_ENDIF)) return false;
          // chunk[8] = sender pubkey
          if (!chunks.get(9).equalsOpCode(OP_CHECKSIG)) return false;
          return true;
      }
docs: Returns whether this script matches the format used for LOCKTIMEVERIFY transactions.