class_docstr: Basic cost model. Change it as we add more cost based rules
class_docstr_tok: ["Basic","cost","model",".","Change","it","as","we","add","more","cost","based","rules"]
code: def __init__(self):
      pass
  
file_path: evadb/evadb/optimizer/cost_model.py
imports: from functools import singledispatch
  from evadb.optimizer.group_expression import GroupExpression
  from evadb.plan_nodes.abstract_plan import AbstractPlan
  from evadb.plan_nodes.apply_and_merge_plan import ApplyAndMergePlan
  from evadb.plan_nodes.hash_join_build_plan import HashJoinBuildPlan
  from evadb.plan_nodes.hash_join_probe_plan import HashJoinProbePlan
  from evadb.plan_nodes.nested_loop_join_plan import NestedLoopJoinPlan
  from evadb.plan_nodes.seq_scan_plan import SeqScanPlan
label_desc: Use image node_id 1 to create a new CostModel object  with example: obj = CostModel()