test_class.file: tx-signer/src/test/java/io/bytom/offline/common/ExpandedPrivateKeyTest.java
test_class.identifier: ExpandedPrivateKeyTest
test_case.body: @Test
      public void testExpandedKey() throws NoSuchAlgorithmException, SignatureException, InvalidKeyException {
          String childXprv = "e8c0965af60563c4cabcf2e947b1cd955c4f501eb946ffc8c3447e5ec8a6335398a3720b3f96077fa187fdde48fe7dc293984b196f5e292ef8ed78fdbd8ed954";
          byte[] z = ExpandedPrivateKey.expandedPrivateKey(Hex.decode(childXprv));
          System.out.println(Hex.toHexString(z));
          //expect: e8c0965af60563c4cabcf2e947b1cd955c4f501eb946ffc8c3447e5ec8a633535b899d45316cd83e027913d3ff3dc52f6a951a686fd2b750099e1f7c70cb98c3
          //        e8c0965af60563c4cabcf2e947b1cd955c4f501eb946ffc8c3447e5ec8a633535b899d45316cd83e027913d3ff3dc52f6a951a686fd2b750099e1f7c70cb98c3
      }
test_case.class_method_signature: ExpandedPrivateKeyTest.testExpandedKey()
test_case.full_signature: @Test public void testExpandedKey()
test_case.identifier: testExpandedKey
test_case.invocations: expandedPrivateKey decode println toHexString
test_case.modifiers: @Test public
test_case.parameters: ()
test_case.return: void
test_case.signature: void testExpandedKey()
focal_class.file: tx-signer/src/main/java/io/bytom/offline/common/ExpandedPrivateKey.java
focal_class.identifier: ExpandedPrivateKey
focal_class.class_method_signature: ExpandedPrivateKey.hmacSha512(byte[] data, byte[] key)
focal_class.full_signature: public static byte[] hmacSha512(byte[] data, byte[] key)
focal_class.identifier: hmacSha512
focal_class.modifiers: public static
focal_class.parameters: (byte[] data, byte[] key)
focal_class.return: byte[]
focal_class.signature: byte[] hmacSha512(byte[] data, byte[] key)
focal_class.class_method_signature: ExpandedPrivateKey.expandedPrivateKey(byte[] data)
focal_class.full_signature: public static byte[] expandedPrivateKey(byte[] data)
focal_class.identifier: expandedPrivateKey
focal_class.modifiers: public static
focal_class.parameters: (byte[] data)
focal_class.return: byte[]
focal_class.signature: byte[] expandedPrivateKey(byte[] data)
focal_method.body: public static byte[] expandedPrivateKey(byte[] data) throws NoSuchAlgorithmException, InvalidKeyException {
          // "457870616e64" is "Expand" hex.
          byte[] res = hmacSha512(data, Hex.decode("457870616e64"));
          for (int i = 0; i <= 31; i++) {
              res[i] = data[i];
          }
          return res;
      }
focal_method.class_method_signature: ExpandedPrivateKey.expandedPrivateKey(byte[] data)
focal_method.full_signature: public static byte[] expandedPrivateKey(byte[] data)
focal_method.identifier: expandedPrivateKey
focal_method.invocations: hmacSha512 decode
focal_method.modifiers: public static
focal_method.parameters: (byte[] data)
focal_method.return: byte[]
focal_method.signature: byte[] expandedPrivateKey(byte[] data)