def vizlib_unary_features(span):
if not span.sentence.is_visual():<EOL><INDENT>return<EOL><DEDENT>for f in get_visual_aligned_lemmas(span):<EOL><INDENT>yield f"<STR_LIT>", DEF_VALUE<EOL><DEDENT>for page in set(span.get_attrib_tokens("<STR_LIT>")):<EOL><INDENT>yield f"<STR_LIT>", DEF_VALUE<EOL><DEDENT>
Visual-related features for a single span