old_contents: from ellipticcurve.ecdsa import Ecdsa
  from ellipticcurve.publicKey import PublicKey
  from ellipticcurve.signature import Signature
  
  from .eventwebhook_header import EventWebhookHeader
  
  class EventWebhook:
      """
      This class allows you to use the Event Webhook feature. Read the docs for
      more details: https://sendgrid.com/docs/for-developers/tracking-events/event
      """
  
      def __init__(self, public_key=None):
          """
          Construct the Event Webhook verifier object
          :param public_key: verification key under Mail Settings
          :type public_key: string
          """
          self.public_key = self.convert_public_key_to_ecdsa(public_key) if public_key else public_key
  
      def convert_public_key_to_ecdsa(self, public_key):
          """
          Convert the public key string to a ECPublicKey.
  
          :param public_key: verification key under Mail Settings
          :type public_key string
          :return: public key using the ECDSA algorithm
          :rtype PublicKey
          """
          return PublicKey.fromPem(public_key)
  
      def verify_signature(self, payload, signature, timestamp, public_key=None):
          """
          Verify signed event webhook requests.
  
          :param payload: event payload in the request body
          :type payload: string
          :param signature: value obtained from the 'X-Twilio-Email-Event-Webhook-Signature' header
          :type signature: string
          :param timestamp: value obtained from the 'X-Twilio-Email-Event-Webhook-Timestamp' header
          :type timestamp: string
          :param public_key: elliptic curve public key
          :type public_key: PublicKey
          :return: true or false if signature is valid
          """
          timestamped_payload = timestamp + payload
          decoded_signature = Signature.fromBase64(signature)
  
          key = public_key or self.public_key
          return Ecdsa.verify(timestamped_payload, decoded_signature, key)
  
new_contents: from ellipticcurve.ecdsa import Ecdsa
  from ellipticcurve.publicKey import PublicKey
  from ellipticcurve.signature import Signature
  
  from .eventwebhook_header import EventWebhookHeader
  
  class EventWebhook:
      """
      This class allows you to use the Event Webhook feature. Read the docs for
      more details: https://sendgrid.com/docs/for-developers/tracking-events/event
      """
  
      def __init__(self, public_key=None):
          """
          Construct the Event Webhook verifier object
          :param public_key: verification key under Mail Settings
          :type public_key: string
          """
          self.public_key = self.convert_public_key_to_ecdsa(public_key) if public_key else public_key
  
      def convert_public_key_to_ecdsa(self, public_key):
          """
          Convert the public key string to a ECPublicKey.
  
          :param public_key: verification key under Mail Settings
          :type public_key string
          :return: public key using the ECDSA algorithm
          :rtype PublicKey
          """
          return PublicKey.fromPem('\n-----BEGIN PUBLIC KEY-----\n'+public_key+'\n-----END PUBLIC KEY-----\n')
  
      def verify_signature(self, payload, signature, timestamp, public_key=None):
          """
          Verify signed event webhook requests.
  
          :param payload: event payload in the request body
          :type payload: string
          :param signature: value obtained from the 'X-Twilio-Email-Event-Webhook-Signature' header
          :type signature: string
          :param timestamp: value obtained from the 'X-Twilio-Email-Event-Webhook-Timestamp' header
          :type timestamp: string
          :param public_key: elliptic curve public key
          :type public_key: PublicKey
          :return: true or false if signature is valid
          """
          timestamped_payload = timestamp + payload
          decoded_signature = Signature.fromBase64(signature)
  
          key = public_key or self.public_key
          return Ecdsa.verify(timestamped_payload, decoded_signature, key)
  
subject: fix event webhook for updated starbank-ecdsa dependency