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Flex value cannot be set for some HBOX elements
I have a Container that holds another Container, and a Form Panel, using HBOX layout. Flex can be set on the chlid Container, but not on the form panel, via Designer. If I add "flex: 1" to the code manually, it works as expected. In general, Flex seems to have this problem -- it is not always there when you would expect it, and instead only the "MaintainFlex" property is available.