@Override
	public void delete(String id) {
		aggregates.remove(id);
	}
In-memory aggregate counter with minute resolution.
<p/>
Note that the data is permanently accumulated, so will grow steadily in size until the host process is restarted.

@author Luke Taylor
@author Eric Bottard
spring-xd-analytics/src/main/java/org/springframework/xd/analytics/metrics/memory/InMemoryAggregateCounterRepository.java