### Question:
ResultSetIterator implements RelationalInput { @Override public ImmutableList<String> columnNames() { return columnNames; } ResultSetIterator(ResultSet resultSet);  ResultSetIterator(ResultSet resultSet, String relationName); @Override boolean hasNext(); @Override List<String> next(); @Override int numberOfColumns(); @Override String relationName(); @Override ImmutableList<String> columnNames(); @Override void close(); static final String UNKNOWN_RELATION_NAME; }### Answer:
@Test public void testColumnNames() throws SQLException { ResultSetIterator resultSetIterator = new ResultSetIterator(twoLinesResultSetFixture.getTestData()); assertEquals(twoLinesResultSetFixture.getExpectedColumnNames(), resultSetIterator.columnNames()); }