Addresses comments in code review.

application/src/main/java/org/opentripplanner/transit/api/request/FindRegularStopsByBoundingBoxRequest.java

@@ -19,7 +19,7 @@ public class FindRegularStopsByBoundingBoxRequest {
 
   private final boolean filterByInUse;
 
- FindRegularStopsByBoundingBoxRequest(
+  FindRegularStopsByBoundingBoxRequest(
     Envelope envelope,
     @Nullable String feedId,
     boolean filterByInUse

application/src/main/java/org/opentripplanner/transit/api/request/FindRegularStopsByBoundingBoxRequestBuilder.java

@@ -12,7 +12,7 @@ public class FindRegularStopsByBoundingBoxRequestBuilder {
 
   private boolean filterByInUse = false;
 
- FindRegularStopsByBoundingBoxRequestBuilder(Envelope envelope) {
+  FindRegularStopsByBoundingBoxRequestBuilder(Envelope envelope) {
     this.envelope = envelope;
   }
 

application/src/main/java/org/opentripplanner/transit/api/request/TripOnServiceDateRequest.java

@@ -23,7 +23,7 @@ public class TripOnServiceDateRequest {
   private final FilterValues<String> netexInternalPlanningCodes;
   private final FilterValues<TripAlteration> alterations;
 
-  protected TripOnServiceDateRequest(
+  TripOnServiceDateRequest(
     RequiredFilterValues<LocalDate> serviceDates,
     FilterValues<FeedScopedId> agencies,
     FilterValues<FeedScopedId> routes,
@@ -41,7 +41,7 @@ protected TripOnServiceDateRequest(
     this.alterations = alterations;
   }
 
-  public static TripOnServiceDateRequestBuilder of(RequiredFilterValues serviceDates) {
+  public static TripOnServiceDateRequestBuilder of(RequiredFilterValues<LocalDate> serviceDates) {
     return new TripOnServiceDateRequestBuilder(serviceDates);
   }
 

application/src/main/java/org/opentripplanner/transit/api/request/TripOnServiceDateRequestBuilder.java

@@ -30,9 +30,9 @@ public class TripOnServiceDateRequestBuilder {
     "alterations",
     List.of()
   );
-  private RequiredFilterValues<LocalDate> serviceDates;
+  private final RequiredFilterValues<LocalDate> serviceDates;
 
-  protected TripOnServiceDateRequestBuilder(RequiredFilterValues serviceDates) {
+  TripOnServiceDateRequestBuilder(RequiredFilterValues<LocalDate> serviceDates) {
     this.serviceDates = serviceDates;
   }
 

application/src/main/java/org/opentripplanner/transit/api/request/TripRequest.java

@@ -17,7 +17,7 @@ public class TripRequest {
   private final FilterValues<String> netexInternalPlanningCodes;
   private final FilterValues<LocalDate> serviceDates;
 
-  protected TripRequest(
+  TripRequest(
     FilterValues<FeedScopedId> agencies,
     FilterValues<FeedScopedId> routes,
     FilterValues<String> netexInternalPlanningCodes,

application/src/main/java/org/opentripplanner/transit/api/request/TripRequestBuilder.java

@@ -21,7 +21,7 @@ public class TripRequestBuilder {
     List.of()
   );
 
-  protected TripRequestBuilder() {}
+  TripRequestBuilder() {}
 
   public TripRequestBuilder withAgencies(FilterValues<FeedScopedId> agencies) {
     this.agencies = agencies;

application/src/main/java/org/opentripplanner/transit/model/filter/transit/RegularStopMatcherFactory.java

@@ -18,9 +18,9 @@ public class RegularStopMatcherFactory {
 
   /**
    * Creates a matcher that filters {@link RegularStop} objects with the provided {@code request}
-   * and {@link inUseProvider}. The {@link inUseProvider} is used to determine if a {@link RegularStop} is
-   * in use. Typically the inUseProvider is a function that checks if the {@link RegularStop} is in
-   * a set of used stops.
+   * and {@code inUseProvider}. The {@code inUseProvider} is used to determine if a {@link RegularStop} is
+   * in use. The inUseProvider is an injected function, because the check is done by the transit service
+   * which has access to all stops and routes. A stop is used if it has routes visiting the stop.
    */
   public static Matcher<RegularStop> of(
     FindRegularStopsByBoundingBoxRequest request,

application/src/main/java/org/opentripplanner/transit/service/TransitService.java

@@ -283,6 +283,7 @@ List<TripTimeOnDate> findTripTimeOnDate(
    * So, if more patterns of mode BUS than RAIL visit the group, the result will be [BUS,RAIL].
    */
   List<TransitMode> findTransitModes(StopLocationsGroup station);
+
   /**
    * For a {@link StopLocation} return its modes.
    * <p>
@@ -303,15 +304,12 @@ List<TripTimeOnDate> findTripTimeOnDate(
   Map<LocalDate, TIntSet> getServiceCodesRunningForDate();
 
   /**
-   * Returns a list of TripOnServiceDates that match the filtering defined in the request.
-   *
-   * @param request - A {@link TripOnServiceDateRequest} object with filtering defined.
-   * @return - A list of {@link TripOnServiceDate}s
+   * Returns a list of {@link TripOnServiceDate}s that match the filtering defined in the request.
    */
   List<TripOnServiceDate> findTripsOnServiceDate(TripOnServiceDateRequest request);
 
   /**
-   * Returns a list of Trips that match the filtering defined in the request.
+   * Returns a list of {@link Trip}s that match the filtering defined in the request.
    *
    */
   List<Trip> getTrips(TripRequest request);
@@ -325,8 +323,8 @@ List<TripTimeOnDate> findTripTimeOnDate(
   boolean containsTrip(FeedScopedId id);
 
   /**
-   * Returns a list of RegularStops that lay within a bounding box and match the other criteria in
-   * the request object.
+   * Returns a list of {@link RegularStop}s that lay within a bounding box and match the other criteria
+   * in the request object.
    */
   Collection<RegularStop> findRegularStopsByBoundingBox(
     FindRegularStopsByBoundingBoxRequest request