def METHOD_NAME(ursulas, test_registry_source_manager):
    his_target = list(ursulas)[4]
    # Vladimir has his own ether address; he hopes to publish it along with Ursula's details
    # so that Alice (or whomever) pays him instead of Ursula, even though Ursula is providing the service.
    # He finds a target and verifies that its interface is valid.
    assert his_target.validate_metadata_signature()
    # Now Vladimir imitates Ursula - copying her public keys and interface info, but inserting his ether address.
    vladimir = remote_vladimir(target_ursula=his_target)
    # Now, even though his public signing key matches Ursulas...
    assert vladimir.metadata().payload.verifying_key == his_target.stamp.as_umbral_pubkey()
    # ...he is unable to pretend that his interface is valid
    # because the validity check contains the canonical public address as part of its message.
    with pytest.raises(vladimir.InvalidNode, match="Metadata signature is invalid"):
        vladimir.validate_metadata_signature()
    # Consequently, the metadata as a whole is also invalid.
    with pytest.raises(vladimir.InvalidNode, match="Metadata signature is invalid"):
        vladimir.validate_metadata()