presto-main/src/main/java/io/prestosql/sql/planner/plan/WindowNode.java/WindowNode/Function
class WindowNode:        @JsonCreator
        public Function(
                @JsonProperty("resolvedFunction") ResolvedFunction resolvedFunction,
                @JsonProperty("arguments") List<Expression> arguments,
                @JsonProperty("frame") Frame frame,
                @JsonProperty("ignoreNulls") boolean ignoreNulls)
        {
            this.resolvedFunction = requireNonNull(resolvedFunction, "Signature is null");
            this.arguments = requireNonNull(arguments, "arguments is null");
            this.frame = requireNonNull(frame, "Frame is null");
            this.ignoreNulls = ignoreNulls;
        }