# File lib/rvg/stretchable.rb, line 17
            def preserve_aspect_ratio(align, meet_or_slice='meet')
                @align = align.to_s
                if @align != 'none'
                    m = /\A(xMin|xMid|xMax)(YMin|YMid|YMax)\z/.match(@align)
                    raise(ArgumentError, "unknown alignment specifier: #{@align}") unless m
                end

                if meet_or_slice
                    meet_or_slice = meet_or_slice.to_s.downcase
                    if meet_or_slice == 'meet' || meet_or_slice == 'slice'
                        @meet_or_slice = meet_or_slice
                    else
                        raise(ArgumentError, "specifier must be `meet' or `slice' (got #{meet_or_slice})")
                    end
                end
                yield(self) if block_given?
                self
            end