<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_visual_aligned_lemmas(mention):
 """Return a generator of the lemmas aligned visually with the Mention. Note that if a candidate is passed in, all of its Mentions will be searched. :param mention: The Mention to evaluate. :rtype: a *generator* of lemmas """

    spans = _to_spans(mention)
    for span in spans:
        sentence = span.sentence
        doc = sentence.document
        # cache features for the entire document
        _preprocess_visual_features(doc)

        for aligned_lemma in sentence._aligned_lemmas:
            yield aligned_lemma