Generates a random password.
        @param length: Integer. Length of a password
        @param special_chars: Boolean. Whether to use special characters !@#$%^&*()_+
        @param digits: Boolean. Whether to use digits
        @param upper_case: Boolean. Whether to use upper letters
        @param lower_case: Boolean. Whether to use lower letters
        @return: String. Random password

def password(
            self,
            length=10,
            special_chars=True,
            digits=True,
            upper_case=True,
            lower_case=True):
        """
        Generates a random password.
        @param length: Integer. Length of a password
        @param special_chars: Boolean. Whether to use special characters !@#$%^&*()_+
        @param digits: Boolean. Whether to use digits
        @param upper_case: Boolean. Whether to use upper letters
        @param lower_case: Boolean. Whether to use lower letters
        @return: String. Random password
        """
        choices = ""
        required_tokens = []
        if special_chars:
            required_tokens.append(
                self.generator.random.choice("!@#$%^&*()_+"))
            choices += "!@#$%^&*()_+"
        if digits:
            required_tokens.append(self.generator.random.choice(string.digits))
            choices += string.digits
        if upper_case:
            required_tokens.append(
                self.generator.random.choice(string.ascii_uppercase))
            choices += string.ascii_uppercase
        if lower_case:
            required_tokens.append(
                self.generator.random.choice(string.ascii_lowercase))
            choices += string.ascii_lowercase

        assert len(
            required_tokens) <= length, "Required length is shorter than required characters"

        # Generate a first version of the password
        chars = self.random_choices(choices, length=length)

        # Pick some unique locations
        random_indexes = set()
        while len(random_indexes) < len(required_tokens):
            random_indexes.add(
                self.generator.random.randint(0, len(chars) - 1))

        # Replace them with the required characters
        for i, index in enumerate(random_indexes):
            chars[index] = required_tokens[i]

        return ''.join(chars)