Revokes a credential.
        :return: None
            Example:
            credential.revoke_credential()

async def revoke_credential(self):
        """
        Revokes a credential.
        :return: None
            Example:
            credential.revoke_credential()
        """
        if not hasattr(IssuerCredential.revoke_credential, "cb"):
            self.logger.debug("vcx_issuer_revoke_credential: Creating callback")
            IssuerCredential.revoke_credential.cb = create_cb(CFUNCTYPE(None, c_uint32, c_uint32))

        c_credential_handle = c_uint32(self.handle)

        await do_call('vcx_issuer_revoke_credential',
                      c_credential_handle,
                      IssuerCredential.revoke_credential.cb)