public static boolean isP2PKH(Script script) {
        List<ScriptChunk> chunks = script.chunks();
        if (chunks.size() != 5)
            return false;
        if (!chunks.get(0).equalsOpCode(OP_DUP))
            return false;
        if (!chunks.get(1).equalsOpCode(OP_HASH160))
            return false;
        byte[] chunk2data = chunks.get(2).data;
        if (chunk2data == null)
            return false;
        if (chunk2data.length != LegacyAddress.LENGTH)
            return false;
        if (!chunks.get(3).equalsOpCode(OP_EQUALVERIFY))
            return false;
        if (!chunks.get(4).equalsOpCode(OP_CHECKSIG))
            return false;
        return true;
    }
@Test
    public void testCreateP2PKHOutputScript() {
        assertTrue(ScriptPattern.isP2PKH(
                ScriptBuilder.createP2PKHOutputScript(keys.get(0))
        ));
    }