public MultiExpression<T> map(UnaryOperator<Expression> mapper) {
    return new MultiExpression<>(
      expressions.stream()
        .map(entry -> entry(entry.result, mapper.apply(entry.expression).simplify()))
        .filter(entry -> entry.expression != Expression.FALSE)
        .toList()
    );
  }
Returns a copy of this multi-expression that replaces every expression using {@code mapper}.
planetiler-core/src/main/java/com/onthegomap/planetiler/expression/MultiExpression.java