def indent(self, indent: str = " " * 4) -> Source:
        """Return a copy of the source object with all lines indented by the
        given indent-string."""
        newsource = Source()
        newsource.raw_lines = self.raw_lines
        newsource.lines = [(indent + line) for line in self.lines]
        return newsource
Return a copy of the source object with all lines indented by the
        given indent-string.
src/_pytest/_code/source.py