docs: def sign_execute_withdrawal(withdrawal_params, private_key):
      """
      Function to execute the withdrawal request by signing the transaction generated from the create withdrawal function.
      Execution of this function is as follows::
  
          sign_execute_withdrawal(withdrawal_params=signable_params, private_key=eth_private_key)
  
      The expected return result for this function is as follows::
  
          {
              'signature': '0x33656f88b364d344e5b04f6aead01cdd3ac084489c39a9efe88c9873249bf1954525b1....'
          }
  
      :param withdrawal_params: The parameters generated by the create function that now require signing.
      :type withdrawal_params: dict
      :param private_key: The Ethereum private key to sign the deposit parameters.
      :type private_key: str
      :return: Dictionary of the signed transaction hash and initiate the withdrawal of ETH via the Switcheo API.
      """
      withdrawal_sha256 = withdrawal_params['transaction']['sha256']
      signed_sha256 = binascii.hexlify(Account.signHash(withdrawal_sha256, private_key=private_key)['signature']).decode()
      return {'signature': '0x' + signed_sha256}