def load(self, requirements_file=None):
        """Load or reload requirements from a requirements.txt file.

        :param requirements_file: if not given, the filename used from
            initialization will be read again.
        """
        if requirements_file is None:
            requirements_file = self.filename
            if requirements_file is None:
                raise ValueError("no filename provided")
        elif isinstance(requirements_file, text_type):
            requirements_file = Path(requirements_file)
        self.clear()
        with requirements_file.open() as f:
            self.loads(f.read())

        if isinstance(requirements_file, (text_type, Path)):
            self.filename = requirements_file
def add(self, dn, object_class=None, attributes=None):

        self.result = { 'dn' : '',
                        'referrals' : None,
                        'description' : 'success',
                        'result' : 0,
                        'message' : '',
                        'type' : 'addResponse'}

        # Check to see if the user exists in the directory
        try:
            index = self._find_user(dn)
        except StopIteration:
            # If we get here the user doesn't exist so continue
            # Create a entry object for the new user
            entry = {}
            entry['dn'] = dn
            entry['attributes'] = attributes
            if object_class != None:
                entry['attributes'].update( {'objectClass': object_class} )
        else:
            # User already exists
            self.result["description"] = "failure"
            self.result["result"] = 68
            self.result["message"] = \
                    "Error entryAlreadyExists for {0}".format(dn)
            return False

        # Add the user entry to the directory
        self.directory.append(entry)

        # Attempt to write changes to disk
        with open(DIRECTORY, 'w+') as f:
            f.write(str(self.directory))

        return True