docs: def generate_join_docs_list(self, left_collection_list, right_collection_list):
          """
              Helper function for merge_join_docs
              :param left_collection_list: Left Collection to be joined
              :type  left_collection_list: MongoCollection
  
              :param right_collection_list: Right Collection to be joined
              :type  right_collection_list: MongoCollection
  
              :return joined_docs: List of docs post join
          """
  
          joined_docs = []
          if (len(left_collection_list) != 0) and (len(right_collection_list) != 0):
              for left_doc in left_collection_list:
                  for right_doc in right_collection_list:
                      l_dict = self.change_dict_keys(left_doc, 'L_')
                      r_dict = self.change_dict_keys(right_doc, 'R_')
                      joined_docs.append(dict(l_dict, **r_dict))
          elif left_collection_list:
              for left_doc in left_collection_list:
                  joined_docs.append(self.change_dict_keys(left_doc, 'L_'))
          else:
              for right_doc in right_collection_list:
                  joined_docs.append(self.change_dict_keys(right_doc, 'R_'))
  
          return joined_docs