class IntervalSkipListSpecHelper::ContainMarkers

def initialize(list, expected_markers)
  @list = list
  @expected_markers = expected_markers
end

def matches?(target_range)
  @target_range = target_range
  @target_range.each do |i|
    markers = @list.containing(i)
    @expected_markers.each do |expected_marker|
      unless markers.include?(expected_marker)
        @failure_message = "Expected #{expected_marker.inspect} to contain #{i}, but it doesn't. #{i} is contained by: #{markers.inspect}."
        return false
      end
    end
    markers.each do |marker|
      unless @expected_markers.include?(marker)
        @failure_message = "Did not expect #{marker.inspect} to contain #{i}. Only expected #{@expected_markers.inspect}."
        return false
      end
    end
  end
  true
end