public GroupingOperation setPrecision(int precision) {
        this.precision = precision;
        return this;
    }
Assigns the precision clause of this. This is the number of intermediate groups returned from each content node
during expression evaluation to give the container node more data to consider when selecting the N groups that are
to be evaluated further.

@param precision the precision to set
@return this, to allow chaining
@see #setMax(int)
container-search/src/main/java/com/yahoo/search/grouping/request/GroupingOperation.java