public void setExecution(Execution execution) {
        if (execution == this.execution) return;

        // If not already coupled, bind the trace of the new execution into the existing execution trace
        if (execution.trace().traceNode().isRoot()
            && execution.trace().traceNode() != this.execution.trace().traceNode().root()) {
            this.execution.trace().traceNode().add(execution.trace().traceNode());
        }

        this.execution = execution;
    }
Sets the execution working on this. For internal use.
container-search/src/main/java/com/yahoo/search/query/Model.java