### Question:
FermaFlowRepository extends FermaGenericRepository<Flow, FlowData, FlowFrame> implements FlowRepository { @Override public Collection<Flow> findByEndpoint(SwitchId switchId, int port) { Map<String, Flow> result = new HashMap<>(); framedGraph().traverse(g -> g.V() .hasLabel(FlowFrame.FRAME_LABEL) .has(FlowFrame.SRC_SWITCH_ID_PROPERTY, SwitchIdConverter.INSTANCE.toGraphProperty(switchId)) .has(FlowFrame.SRC_PORT_PROPERTY, port)) .frameExplicit(FlowFrame.class) .forEachRemaining(frame -> result.put(frame.getFlowId(), new Flow(frame))); framedGraph().traverse(g -> g.V() .hasLabel(FlowFrame.FRAME_LABEL) .has(FlowFrame.DST_SWITCH_ID_PROPERTY, SwitchIdConverter.INSTANCE.toGraphProperty(switchId)) .has(FlowFrame.DST_PORT_PROPERTY, port)) .frameExplicit(FlowFrame.class) .forEachRemaining(frame -> result.put(frame.getFlowId(), new Flow(frame))); return result.values(); } FermaFlowRepository(FramedGraphFactory<?> graphFactory, FlowPathRepository flowPathRepository,
                               TransactionManager transactionManager); @Override long countFlows(); @Override Collection<Flow> findAll(); @Override boolean exists(String flowId); @Override Optional<Flow> findById(String flowId); @Override Collection<Flow> findByGroupId(String flowGroupId); @Override Collection<String> findFlowsIdByGroupId(String flowGroupId); @Override Collection<Flow> findWithPeriodicPingsEnabled(); @Override Collection<Flow> findByEndpoint(SwitchId switchId, int port); @Override Optional<Flow> findByEndpointAndVlan(SwitchId switchId, int port, int vlan); @Override Optional<Flow> findOneSwitchFlowBySwitchIdInPortAndOutVlan(SwitchId switchId, int inPort, int outVlan); @Override Collection<Flow> findOneSwitchFlows(SwitchId switchId); @Override Collection<Flow> findByEndpointWithMultiTableSupport(SwitchId switchId, int port); @Override Collection<String> findFlowsIdsByEndpointWithMultiTableSupport(SwitchId switchId, int port); @Override Collection<String> findFlowIdsForMultiSwitchFlowsByEndpointWithMultiTableSupport(SwitchId switchId,
                                                                                            int port); @Override Collection<Flow> findByEndpointSwitch(SwitchId switchId); @Override Collection<Flow> findByEndpointSwitchWithMultiTableSupport(SwitchId switchId); @Override Collection<Flow> findByEndpointSwitchWithEnabledLldp(SwitchId switchId); @Override Collection<Flow> findByEndpointSwitchWithEnabledArp(SwitchId switchId); @Override Collection<Flow> findInactiveFlows(); @Override Collection<Flow> findByFlowFilter(FlowFilter flowFilter); @Override Optional<String> getOrCreateFlowGroupId(String flowId); @Override void updateStatus(@NonNull String flowId, @NonNull FlowStatus flowStatus); @Override void updateStatus(String flowId, FlowStatus flowStatus, String flowStatusInfo); @Override void updateStatusInfo(String flowId, String flowStatusInfo); @Override @TransactionRequired void updateStatusSafe(Flow flow, FlowStatus flowStatus, String flowStatusInfo); @Override long computeFlowsBandwidthSum(Set<String> flowIds); @Override Optional<Flow> remove(String flowId);  }### Answer:
@Test public void shouldFindFlowByEndpoint() { Flow flow = createTestFlow(TEST_FLOW_ID, switchA, switchB); Collection<Flow> foundFlows = flowRepository.findByEndpoint(TEST_SWITCH_A_ID, 1); Set<String> foundFlowIds = foundFlows.stream().map(foundFlow -> flow.getFlowId()).collect(Collectors.toSet()); assertThat(foundFlowIds, Matchers.hasSize(1)); }