You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: state_finders.rb
    path of file: ./repos/manageiq/app/models/metric/ci_mixin
    
    the code of the file until where you have to start completion: module Metric::CiMixin::StateFinders
  # load from cache or create a VimPerformanceState for a given timestamp
  #
  # for a cache:
  #   use preload to populate vim_performance_states associations
  #     this loads all records
  #     
    
  def vim_performance_state_for_ts(ts)
    ts = Time.parse(ts).utc if ts.kind_of?(String)
    ts_iso = ts.utc.iso8601
    return nil unless respond_to?(:vim_performance_states)

    @states_by_ts ||= {}
    state = @states_by_ts[ts_iso]
    if state.nil?
      # using preloaded vim_performance_states association
      if vim_performance_states.loaded?
        # Look for requested time in cache
        state = vim_performance_states.detect { |s| s.timestamp == ts }
        if state.nil?
          # Look for state for current hour in cache
          ts_iso_now = Metric::Helper.nearest_hourly_timestamp(Time.now.utc)
          t = ts_iso_now.to_time(:utc)
          state = vim_performance_states.detect { |s| s.timestamp == t }
        end