### Question:
BigtableTableAdminGrpcClient implements BigtableTableAdminClient { @Override public ListenableFuture<ListSnapshotsResponse> listSnapshotsAsync(ListSnapshotsRequest request) { return createUnaryListener(request, listSnapshotsRpc, request.getParent()).getAsyncResult(); } BigtableTableAdminGrpcClient(
      Channel channel,
      ScheduledExecutorService retryExecutorService,
      BigtableOptions bigtableOptions); @Override ListTablesResponse listTables(ListTablesRequest request); @Override ListenableFuture<ListTablesResponse> listTablesAsync(ListTablesRequest request); @Override Table getTable(GetTableRequest request); @Override ListenableFuture<Table> getTableAsync(GetTableRequest request); @Override Table createTable(CreateTableRequest request); @Override ListenableFuture<Table> createTableAsync(CreateTableRequest request); @Override Table modifyColumnFamily(ModifyColumnFamiliesRequest request); @Override ListenableFuture<Table> modifyColumnFamilyAsync(ModifyColumnFamiliesRequest request); @Override void deleteTable(DeleteTableRequest request); @Override ListenableFuture<Empty> deleteTableAsync(DeleteTableRequest request); @Override void dropRowRange(DropRowRangeRequest request); @Override ListenableFuture<Empty> dropRowRangeAsync(DropRowRangeRequest request); @Override void waitForReplication(BigtableTableName tableName, long timeout); @Override Policy getIamPolicy(GetIamPolicyRequest request); @Override Policy setIamPolicy(SetIamPolicyRequest request); @Override TestIamPermissionsResponse testIamPermissions(TestIamPermissionsRequest request); @Override ListenableFuture<Operation> snapshotTableAsync(SnapshotTableRequest request); @Override ListenableFuture<Snapshot> getSnapshotAsync(GetSnapshotRequest request); @Override ListenableFuture<ListSnapshotsResponse> listSnapshotsAsync(ListSnapshotsRequest request); @Override ListenableFuture<Empty> deleteSnapshotAsync(DeleteSnapshotRequest request); @Override ListenableFuture<Operation> createTableFromSnapshotAsync(
      CreateTableFromSnapshotRequest request);  }### Answer:
@Test public void testListSnapshots() throws Exception { ListSnapshotsRequest request = ListSnapshotsRequest.newBuilder().setParent(TABLE_NAME).build(); complete(); defaultClient.listSnapshotsAsync(request).get(1, TimeUnit.SECONDS); verifyRequestCalled(request); }