def ufo_create_background_layer_for_all_glyphs(ufo_font):<EOL>
if "<STR_LIT>" in ufo_font.layers:<EOL><INDENT>background = ufo_font.layers["<STR_LIT>"]<EOL><DEDENT>else:<EOL><INDENT>background = ufo_font.newLayer("<STR_LIT>")<EOL><DEDENT>for glyph in ufo_font:<EOL><INDENT>if glyph.name not in background:<EOL><INDENT>background.newGlyph(glyph.name)<EOL><DEDENT><DEDENT>
Create a background layer for all glyphs in ufo_font if not present to
    reduce roundtrip differences.