docs: def create_withdrawal(self, asset, amount, private_key):
          """
          Function to create a withdrawal request by generating a withdrawal ID request from the Switcheo API.
          Execution of this function is as follows::
  
              create_withdrawal(asset="SWTH", amount=1.1, private_key=kp)
  
          The expected return result for this function is as follows::
  
              {
                  'id': 'a5a4d396-fa9f-4191-bf50-39a3d06d5e0d'
              }
  
          :param asset:  Script Hash of asset ID from the available products.
          :type asset: str
          :param amount: The amount of coins/tokens to be withdrawn.
          :type amount: float
          :param private_key: The Private Key (ETH) or KeyPair (NEO) for the wallet being used to sign deposit message.
          :type private_key: KeyPair or str
          :return: Dictionary with the withdrawal ID generated by the Switcheo API.
          """
          signable_params = {
              'blockchain': self.blockchain,
              'asset_id': asset,
              'amount': str(self.blockchain_amount[self.blockchain](amount)),
              'timestamp': get_epoch_milliseconds(),
              'contract_hash': self.contract_hash
          }
          api_params = self.sign_create_withdrawal_function[self.blockchain](signable_params, private_key)
          return self.request.post(path='/withdrawals', json_data=api_params)