| glyphIndex | The index of the glyph that should be loaded. |
| flags | The glyph loading flag that should be used to load the glyph. |
| glyph | The glyph using the provided index or the .notdef glyph (index 0) if no glyph was found at that index. |
bool Returns true if a glyph exists at the given index. Otherwise returns false.
Try loading the glyph for the given index value and if available populate the glyph.