### Question:
TableStorageStatesImpl implements TableStorageStates, Closeable { @Override public long getDataSize(TableReference tableReference) { ImmutableMap<TableReference, Long> dataSizes = myTableSizes.get(); if (dataSizes != null && dataSizes.containsKey(tableReference)) { return dataSizes.get(tableReference); } return 0; } private  TableStorageStatesImpl(Builder builder); @Override long getDataSize(TableReference tableReference); @Override long getDataSize(); @Override void close(); static Builder builder();  }### Answer:
@Test public void testTableStatesForNoTables() { assertThat(myTableStorageeStatesImpl.getDataSize(new TableReference("non_existing_keyspace", "non_existing_table"))).isEqualTo(0); assertThat(myTableStorageeStatesImpl.getDataSize()).isEqualTo(0); }