columns {
  name: "key"
  type {
    type_id: UTF8
  }
}
columns {
  name: "key1"
  type {
    type_id: UTF8
  }
}
columns {
  name: "subkey"
  type {
    type_id: UTF8
  }
}
columns {
  name: "subkey1"
  type {
    type_id: UTF8
  }
}
columns {
  name: "value"
  type {
    type_id: UTF8
  }
}
rows {
  items {
    text_value: "1"
  }
  items {
    text_value: "1"
  }
  items {
    text_value: "a"
  }
  items {
    text_value: "a"
  }
  items {
    text_value: "value1_1"
  }
}
rows {
  items {
    text_value: "4"
  }
  items {
    text_value: "4"
  }
  items {
    text_value: "d"
  }
  items {
    text_value: "d"
  }
  items {
    text_value: "value1_4"
  }
}
