PangoLayout.pangoLayoutGetLineReadonly(object, line)objectlinepango_layout_get_line_count(layout) - 1, inclusive.PangoLayoutLine] the requested PangoLayoutLine, or NULL if the
index is out of range. This layout line can
be ref'ed and retained, but will become invalid
if changes are made to the PangoLayout.
No changes should be made to the line.pangoLayoutGetLine,
but the user is not expected
to modify the contents of the line (glyphs, glyph widths, etc.).
Since 1.16