### Question:
CryptographyUtils { @Nullable public static String makeSHA1(@Nullable final String value) { if (value == null || value.length() == 0) { return value; } final String hash; try { final MessageDigest digest = MessageDigest.getInstance("SHA-1"); byte[] bytes = value.getBytes(Cryptography.CHARSET_NAME); digest.update(bytes, 0, bytes.length); bytes = digest.digest(); hash = bytesToHex(bytes); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); throw new AssertionError("SHA-1 function is not available!"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); throw new AssertionError(Cryptography.CHARSET_NAME + " encoding is not supported!"); } return hash; } private  CryptographyUtils(); @Nullable static String encrypt(@Nullable final String value, @NonNull final Encrypto encrypto); @Nullable static String decrypt(@Nullable final String value, @NonNull final Decrypto decrypto); @Nullable static String makeSHA1(@Nullable final String value);  }### Answer:
@Test public void testMakeSha1() { assertThat(CryptographyUtils.makeSHA1(null), is(nullValue())); assertThat(CryptographyUtils.makeSHA1(""), is("")); assertThat(CryptographyUtils.makeSHA1("android"), is("e4bbe5b7a4c1eb55652965aee885dd59bd2ee7f4")); assertThat(CryptographyUtils.makeSHA1("0123456789"), is("87acec17cd9dcd20a716cc2cf67417b71c8a7016")); }