code: func (e *joinReOrderSolver) makeBushyJoin(cartesianJoinGroup []LogicalPlan) {
  	for len(cartesianJoinGroup) > 1 {
  		resultJoinGroup := make([]LogicalPlan, 0, len(cartesianJoinGroup))
  		for i := 0; i < len(cartesianJoinGroup); i += 2 {
  			if i+1 == len(cartesianJoinGroup) {
  				resultJoinGroup = append(resultJoinGroup, cartesianJoinGroup[i])
  				break
  			}
  			resultJoinGroup = append(resultJoinGroup, e.newJoin(cartesianJoinGroup[i], cartesianJoinGroup[i+1]))
  		}
  		cartesianJoinGroup = resultJoinGroup
  	}
  	e.resultJoin = cartesianJoinGroup[0]
  }
docs: // Make cartesian join as bushy tree.