### Question:
CosignatureSignedTransaction extends AggregateTransactionCosignature { public String getParentHash() { return parentHash; } CosignatureSignedTransaction(
      BigInteger version, String parentHash, String signature, PublicAccount signer); String getParentHash();  }### Answer:
@Test void createACosignatureSignedTransactionViaConstructor() { PublicAccount signer = Account.generateNewAccount(NetworkType.MIJIN_TEST).getPublicAccount(); CosignatureSignedTransaction cosignatureSignedTransaction = new CosignatureSignedTransaction( AggregateTransactionCosignature.DEFAULT_VERSION, "parentHash", "signature", signer); assertEquals( AggregateTransactionCosignature.DEFAULT_VERSION, cosignatureSignedTransaction.getVersion()); assertEquals("parentHash", cosignatureSignedTransaction.getParentHash()); assertEquals("signature", cosignatureSignedTransaction.getSignature()); assertEquals(signer, cosignatureSignedTransaction.getSigner()); }