Compatibility with x11rb 0.13 The new version of x11rb changed HierarchyInfo.flags from a u32 to a HierarchyMask. HierarchyMask implements Into<u32>.
Use of u32::from on info.flags is a no-op with x11rb 0.10 and lower because flags is already a u32. With x11rb 0.13, this will convert the flags to a u32.
