elasticSearch RangeQuery范围查询from to的理解

Elasticsearch Guide 选择版本号来查询对应的文档内容:
https://www.elastic.co/guide/en/elasticsearch/reference/6.7/index.html

需要根据版本号来查询：
Elasticsearch Guide [6.7] Query DSL Term level queries Range Query
https://www.elastic.co/guide/en/elasticsearch/reference/6.7/query-dsl-range-query.html

查看RangeQueryBuilder.java源码内容：
public static final boolean DEFAULT_INCLUDE_UPPER = true; //默认是包含
public static final boolean DEFAULT_INCLUDE_LOWER = true; //默认是包含

private boolean includeLower = DEFAULT_INCLUDE_LOWER;
private boolean includeUpper = DEFAULT_INCLUDE_UPPER;

/**
* The from part of the range query. Null indicates unbounded. 默认是包含(大于等于)
*/
public RangeQueryBuilder from(Object from) {
return from(from, this.includeLower);
}

/**
* The from part of the range query. Null indicates unbounded. 大于
*/
public RangeQueryBuilder gt(Object from) {
return from(from, false);
}

/**
* The from part of the range query. Null indicates unbounded. 大于等于
*/
public RangeQueryBuilder gte(Object from) {
return from(from, true);
}

/**
* The to part of the range query. Null indicates unbounded. 默认是包含(小于等于)
*/
public RangeQueryBuilder to(Object to) {
return to(to, this.includeUpper);
}

/**
* The to part of the range query. Null indicates unbounded. 小于
*/
public RangeQueryBuilder lt(Object to) {
return to(to, false);
}

/**
* The to part of the range query. Null indicates unbounded. 小于等于
*/
public RangeQueryBuilder lte(Object to) {
return to(to, true);
}

demo代码(三种方式)：
boolQueryBuilder.must(QueryBuilders.rangeQuery("field1").to(reqVO.getDate2()));
boolQueryBuilder.must(QueryBuilders.rangeQuery("field2").from(reqVO.getDate1()));
boolQueryBuilder.must(QueryBuilders.rangeQuery("field2").from(reqVO.getDate1())).to(reqVO.getDate2()));