### Question:
RecoveryCodeGenerator { public String generateDelimitedCodeWithSpecifics(CodeGeneratorSource alphabet, char delimiter, Map<Integer, Character> specifics, int... groups) { StringBuilder codeBuilder = new StringBuilder(generateDelimitedCode(alphabet, delimiter, groups)); int maxLength = codeBuilder.length(); for(Map.Entry<Integer, Character> specific : specifics.entrySet()) { Reject.ifTrue(specific.getKey() < 0 || specific.getKey() > maxLength); Reject.ifNull(specific.getValue()); codeBuilder.replace(specific.getKey(), specific.getKey() + 1, String.valueOf(specific.getValue())); } return codeBuilder.toString(); } RecoveryCodeGenerator(SecureRandom secureRandom, int retryMaximum); @Inject  RecoveryCodeGenerator(SecureRandom secureRandom); String generateCode(CodeGeneratorSource alphabet, int length); String generateDelimitedCode(CodeGeneratorSource alphabet, char delimiter, int... groups); String generateDelimitedCodeWithSpecifics(CodeGeneratorSource alphabet, char delimiter,
                                                       Map<Integer, Character> specifics, int... groups); String[] generateCodes(int numCodes, CodeGeneratorSource alphabet, boolean allowDuplicates); String[] generateCodes(int numCodes, CodeGeneratorSource alphabet, int length, boolean allowDuplicates); String[] generateDelimitedCodes(int numCodes, CodeGeneratorSource alphabet,
                                           char delimiter, boolean allowDuplicates, int... groups); String[] generateDelimitedCodesWithSpecifics(int numCodes, CodeGeneratorSource alphabet,
                                                        char delimiter, Map<Integer, Character> specifics,
                                                        boolean allowDuplicates, int... groups); final static int DEFAULT_LENGTH; final static int DEFAULT_RETRIES; }### Answer:
@Test (expectedExceptions = NullPointerException.class) public void shouldErrorNullAlphabet6() throws CodeException { Map<Integer, Character> map = new HashMap<>(); map.put(0, 'L'); recoveryCodeGenerator.generateDelimitedCodeWithSpecifics(null, '-', map, 1); }