assertTrue(blocks.hasNext());
assertEquals(ControlBlock.LIST_BEGIN, blocks.next());
assertTrue(blocks.hasNext());
Object block = blocks.next();
assertTrue(block instanceof MetadataWrapper);
TupleMetadata meanMetadata = (TupleMetadata)((MetadataWrapper)block).getMetadata();
assertEquals("X", meanMetadata.getColumnMetadata(0).getName());
assertEquals("Y", meanMetadata.getColumnMetadata(1).getName());
assertTrue(blocks.hasNext());
Tuple tuple = (Tuple)blocks.next();
assertEquals(new Double(3), tuple.getDouble(0));
assertEquals(new Double(5), tuple.getDouble(1));
assertTrue(blocks.hasNext());