def encompass(self):
        """
        Called when parallelize is False.
        This function will generate the file names in a directory tree by walking the tree either top-down or
        bottom-up. For each directory in the tree rooted at directory top (including top itself), it yields a 3-tuple
        (dirpath, dirnames, filenames).
        """
        self._printer('Standard Walk')
        count = Counter(length=3)
        for directory in self.directory:
            for root, directories, files in os.walk(directory, topdown=self.topdown):
                root = root[len(str(directory)) + 1:]
                self._printer(str(count.up) + ": Explored path - " + str(root), stream=True)
                for filename in files:
                    fullname = os.path.join(root, filename)
                    # Join the two strings in order to form the full filepath.
                    self.add_path(directory, fullname)