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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_metadata(bind):
 """Return the metadata for a bind."""

    if bind == '':
        bind = None
    m = MetaData()
    for t in target_metadata.tables.values():
        if t.info.get('bind_key') == bind:
            t.tometadata(m)
    return m