PlanNode source = planRewriter.rewrite(node.getSource(), context);
ImmutableMap.Builder<Symbol, FunctionHandle> functionInfos = ImmutableMap.builder();
ImmutableMap.Builder<Symbol, FunctionCall> functionCalls = ImmutableMap.builder();
for (Map.Entry<Symbol, FunctionCall> entry : node.getWindowFunctions().entrySet()) {
Symbol symbol = entry.getKey();
Symbol canonical = canonicalize(symbol);
functionCalls.put(canonical, (FunctionCall) canonicalize(entry.getValue()));
functionInfos.put(canonical, node.getFunctionHandles().get(symbol));
}
ImmutableMap.Builder<Symbol, SortItem.Ordering> orderings = ImmutableMap.builder();