Retrieve the content of the requested resource which is located
        at the given absolute path.
        This method should either return a byte string or an iterator
        of byte strings.  The latter is preferred for large files
        as it helps reduce memory fragmentation.

def get_content(self, start=None, end=None):
        """
        Retrieve the content of the requested resource which is located
        at the given absolute path.
        This method should either return a byte string or an iterator
        of byte strings.  The latter is preferred for large files
        as it helps reduce memory fragmentation.
        """
        with open(self.filepath, "rb") as file:
            if start is not None:
                file.seek(start)
            if end is not None:
                remaining = end - (start or 0)
            else:
                remaining = None
            while True:
                chunk_size = 64 * 1024
                if remaining is not None and remaining < chunk_size:
                    chunk_size = remaining
                chunk = file.read(chunk_size)
                if chunk:
                    if remaining is not None:
                        remaining -= len(chunk)
                    yield chunk
                else:
                    if remaining is not None:
                        assert remaining == 0
                    return