this.objectSource = new MockObjectSource(4);
this.sink = new MockLeftTupleSink();
this.accumulator = new MockAccumulator();
final ObjectType srcObjType = new ClassObjectType(String.class);
final Pattern sourcePattern = new Pattern(0,
srcObjType);
this.accumulate = new Accumulate(sourcePattern,
new Declaration[0],
new Accumulator[]{this.accumulator},