Validate that non-edges do not have the in/out properties defined.

def _validate_non_edges_do_not_have_edge_like_properties(class_name, properties):
    """Validate that non-edges do not have the in/out properties defined."""
    has_source = EDGE_SOURCE_PROPERTY_NAME in properties
    has_destination = EDGE_DESTINATION_PROPERTY_NAME in properties

    if has_source or has_destination:
        raise IllegalSchemaStateError(u'Found a non-edge class that defines edge-like "in" or '
                                      u'"out" properties: {} {}'.format(class_name, properties))

    for property_name, property_descriptor in six.iteritems(properties):
        if property_descriptor.type_id == PROPERTY_TYPE_LINK_ID:
            raise IllegalSchemaStateError(u'Non-edge class "{}" has a property of type Link, this '
                                          u'is not allowed: {}'.format(class_name, property_name))