for

# File lib/bundler/version_ranges.rb, line 45
    def self.for(requirement)
      ranges = requirement.requirements.map do |op, v|
        case op
        when "=" then ReqR.new(ReqR::Endpoint.new(v, true), ReqR::Endpoint.new(v, true))
        when "!=" then NEq.new(v)
        when ">=" then ReqR.new(ReqR::Endpoint.new(v, true), ReqR::Endpoint.new(ReqR::INFINITY, false))
        when ">" then ReqR.new(ReqR::Endpoint.new(v, false), ReqR::Endpoint.new(ReqR::INFINITY, false))
        when "<" then ReqR.new(ReqR::Endpoint.new(ReqR::ZERO, true), ReqR::Endpoint.new(v, false))
        when "<=" then ReqR.new(ReqR::Endpoint.new(ReqR::ZERO, true), ReqR::Endpoint.new(v, true))
        when "~>" then ReqR.new(ReqR::Endpoint.new(v, true), ReqR::Endpoint.new(v.bump, false))
        else raise "unknown version op #{op} in requirement #{requirement}"
        end
      end.uniq
      ranges, neqs = ranges.partition {|r| !r.is_a?(NEq) }

      [ranges.sort_by {|range| [range.left.version, range.left.inclusive ? 0 : 1] }, neqs.map(&:version)]
    end