docs: def compile_swagger_schema(schema_dir, resource_listing):
      """Build a SwaggerSchema from various files.
  
      :param schema_dir: the directory schema files live inside
      :type schema_dir: string
      :returns: a SwaggerSchema object
      """
      mapping = build_schema_mapping(schema_dir, resource_listing)
      resource_validators = ingest_resources(mapping, schema_dir)
      endpoints = list(build_swagger_12_endpoints(resource_listing, mapping))
      return SwaggerSchema(endpoints, resource_validators)