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# format_number()
 -  takes a number as its first argument
 # TODO  takes the current user culture if no second argument is given
 -  takes a number as its first argument
 -  takes a number as its first argument
 -  takes a number as its first argument
 -  takes a number as its first argument
 -  takes a number as its first argument
 -  takes a number as its first argument
 -  takes a number as its first argument
 -  takes a number as its first argument
 -  takes a number as its first argument
 -  takes a number as its first argument
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