This test checks that the justify-content property is applied correctly when using content-position values.
direction: LTR | justify-content: 'center'
direction: LTR | justify-content: 'left'
direction: LTR | justify-content: 'right'
direction: LTR | justify-content: 'start'
direction: LTR | justify-content: 'end'
direction: LTR | justify-content: 'flex-start'
direction: LTR | justify-content: 'flex-end'
direction: LTR | justify-content: 'auto' (resolved to 'start')
direction: RTL | justify-content: 'center'
direction: RTL | justify-content: 'left'
direction: RTL | justify-content: 'right'
direction: RTL | justify-content: 'start'
direction: RTL | justify-content: 'end'