text: from datetime import datetime
  from pydantic import BaseModel
  
  class TransactionInDB(BaseModel):
      id_transaction: int = 0
      username: str
      date: datetime = datetime.now()
      value: int
      actual_balance: int
  
  database_transactions = []
  generator = {"id":0}
  
  def save_transaction(transaction_in_db: TransactionInDB):
      generator["id"] = generator["id"] + 1
      transaction_in_db.id_transaction = generator["id"]
      database_transactions.append(transaction_in_db)
      return transaction_in_db