docs: public void promoteSinglePartitionInfo(
              HashMap<AbstractExpression, Set<AbstractExpression>> valueEquivalence,
              Set< Set<AbstractExpression> > eqSets) {
          assert(getScanPartitioning() != null);
          if (getScanPartitioning().getCountOfPartitionedTables() == 0 ||
                  getScanPartitioning().requiresTwoFragments()) {
              return;
          }
  
          // This subquery is a single partitioned query on partitioned tables
          // promoting the single partition expression up to its parent level.
          AbstractExpression spExpr = getScanPartitioning().singlePartitioningExpression();
  
          for (SchemaColumn col: m_partitioningColumns) {
              AbstractExpression tveKey = col.getExpression();
              assert(tveKey instanceof TupleValueExpression);
              Set<AbstractExpression> values = null;
              if (valueEquivalence.containsKey(tveKey)) {
                  values = valueEquivalence.get(tveKey);
              }
              else if (valueEquivalence.containsKey(spExpr)) {
                  values = valueEquivalence.get(spExpr);
              }
              else {
                  for (SchemaColumn otherCol: m_partitioningColumns) {
                      if (col != otherCol &&
                          valueEquivalence.containsKey(otherCol.getExpression())) {
                          values = valueEquivalence.get(otherCol.getExpression());
                          break;
                      }
                  }
                  if (values == null) {
                      values = new HashSet<>();
                  }
              }
              updateEqualSets(values, valueEquivalence, eqSets, tveKey, spExpr);
          }
      }