def METHOD_NAME(
    self, anchor: RawSegment, new_segment: RawSegment, trim: int = 0
) -> None:
    """Copy the depth info for one segment and apply to another.
    This mutates the existing depth map. That's ok because it's
    an idempotent operation and uuids should be unique.
    This is used in edits to a reflow sequence when new segments are
    inserted and can't infer their own depth info.
    NOTE: we don't remove the old one because it causes no harm.
    """
    self.depth_info[new_segment.uuid] = self.get_depth_info(anchor).trim(trim)