format: "%DYNAMIC_METADATA(com.test:test_key)%|%DYNAMIC_METADATA(com.test:test_obj)%|%DYNAMIC_METADATA(com.test:test_obj:inner_key)%"
stream_info {
  dynamic_metadata {
    filter_metadata {
      key: "com.test"
      value: {
        fields {
          key: "test_key"
          value: { string_value: "test_value" }
        }
        fields {
          key: "test_obj"
          value: {
            struct_value {
              fields {
                key: "inner_key"
                value: { string_value: "inner_value" }
              }
            }
          }
        }
      }
    }
  }
}
