<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def uniquelines(q):
 """ Given all the facets, convert it into a set of unique lines. Specifically used for converting convex hull facets into line pairs of coordinates. Args: q: A 2-dim sequence, where each row represents a facet. E.g., Returns: setoflines: """

    setoflines = set()
    for facets in q:
        for line in itertools.combinations(facets, 2):
            setoflines.add(tuple(sorted(line)))
    return setoflines