public GemFireSource cacheEventExpression(String cacheEventExpression) {
		this.cacheEventExpression = cacheEventExpression;
		return this;
	}
Set the cache key. Defaults to stream name

@param cacheEventExpression a SpEL expression evaluating the payload
@return this
spring-xd-test-fixtures/src/main/java/org/springframework/xd/test/fixtures/GemFireSource.java