/** * Tests whether this is a unit-valued answer. A unit answer appended to * something yields the unit answer. A unit answer joined to something yields * the same something. Notionally, the unit answer has zero columns and one * row. * * @return The Unconstrained value * @throws TuplesException EXCEPTION TO DO */ public boolean isUnconstrained() throws TuplesException { return (getVariables().length == 0) && (getRowCardinality() > Cursor.ZERO); }