Adds sub-blocks at the specified indentation level, which defaults to 0.

        Nones are skipped.

        Returns the parent block itself, useful for chaining.

def add(self, *blocks, indentation=0) -> "CodeBlock":
        """
        Adds sub-blocks at the specified indentation level, which defaults to 0.

        Nones are skipped.

        Returns the parent block itself, useful for chaining.
        """
        for block in blocks:
            if block is not None:
                self._blocks.append((indentation, block))

        return self