code: public static StepContextFetcher fetcher(final String pathFlowSid, 
                                               final String pathEngagementSid, 
                                               final String pathStepSid) {
          return new StepContextFetcher(pathFlowSid, pathEngagementSid, pathStepSid);
      }
docs: Create a StepContextFetcher to execute fetch.
  
  @param pathFlowSid Flow Sid.
  @param pathEngagementSid Engagement Sid.
  @param pathStepSid Step Sid.
  @return StepContextFetcher capable of executing the fetch