module Tins::Unit

def parse(string, format: '%f %U', unit: ?b, prefix: nil)

the prefixes specified by +prefix+.
Parse the string +string+ if it matches +format+ with the unit +unit+ and 
def parse(string, format: '%f %U', unit: ?b, prefix: nil)
  prefixes = prefixes(prefix)
  FormatParser.new(format, UnitParser.new(string, unit, prefixes)).parse
end