For given `file_obj` return iterator, which will read the file in
        `self.read_bs` chunks.

        Args:
            file_obj (file): File-like object.

        Return:
            iterator: Iterator reading the file-like object in chunks.

def _get_file_iterator(self, file_obj):
        """
        For given `file_obj` return iterator, which will read the file in
        `self.read_bs` chunks.

        Args:
            file_obj (file): File-like object.

        Return:
            iterator: Iterator reading the file-like object in chunks.
        """
        file_obj.seek(0)

        return iter(lambda: file_obj.read(self.read_bs), '')